Solve the following system of equations

3x - 2y =55

-2x - 3y = 14

Answers

Answer 1

Answer:

The solution is:

[tex](\frac{137}{13}, -\frac{152}{13})[/tex]

Step-by-step explanation:

We have the following equations

[tex]3x - 2y =55[/tex]

[tex]-2x - 3y = 14[/tex]

To solve the system multiply by [tex]\frac{3}{2}[/tex] the second equation and add it to the first equation

[tex]-2*\frac{3}{2}x - 3\frac{3}{2}y = 14\frac{3}{2}[/tex]

[tex]-3x - \frac{9}{2}y = 21[/tex]

[tex]3x - 2y =55[/tex]

---------------------------------------

[tex]-\frac{13}{2}y=76[/tex]

[tex]y=-76*\frac{2}{13}[/tex]

[tex]y=-\frac{152}{13}[/tex]

Now substitute the value of y in any of the two equations and solve for x

[tex]-2x - 3(-\frac{152}{13}) = 14[/tex]

[tex]-2x +\frac{456}{13} = 14[/tex]

[tex]-2x= 14-\frac{456}{13}[/tex]

[tex]-2x=-\frac{274}{13}[/tex]

[tex]x=\frac{137}{13}[/tex]

The solution is:

[tex](\frac{137}{13}, -\frac{152}{13})[/tex]

Answer 2

Answer:

x = 411/39 and y = -152/13

Step-by-step explanation:

It is given that,

3x - 2y = 55    ----(1)

-2x - 3y = 14  ---(2)

To find the solution of given equations

eq(1)  * 2  ⇒

6x - 4y = 110  ---(3)

eq(2) * 3  ⇒

-6x - 9y = 42  ---(4)

eq(3) + eq(4)  ⇒

6x - 4y = 110  ---(3)

-6x - 9y = 42 ---(4)

  0 - 13y = 152

y = -152/13

Substitute the value of y in eq (1)

3x - 2y = 55    ----(1)

3x - 2*(-152/13) = 55

3x + 304/13 = 55

3x = 411/13

x = 411/39

Therefore x = 411/39 and y = -152/13


Related Questions

which statement regarding the function y=sin(x) is true?

a. Reflection over the y-axis will not change the graph since sine is an even function
b. Sin(x)=sin(-x)
c. Reflection over either the x-axis or y-axis will change the graph
d. Sin(x)=-sin(x)

Answers

Answer:

c. Reflection over either the x-axis or y-axis will change the graph

Step-by-step explanation:a. Reflection over the y-axis will not change the graph since sine is an even function.

This is false because [tex]y=sin(x)[/tex] is an odd function, not an even one. This means that [tex]sin(-x)=-sin(x)[/tex], and a reflection over the y-axis will change the graph.

b. Sin(x)=sin(-x)

This is false because we said that [tex]sin(-x)=-sin(x)[/tex]

c. Reflection over either the x-axis or y-axis will change the graph

This is true. Since [tex]sin(x)[/tex] is an odd function, then reflection over either the x-axis or y-axis will change the graph as we said in a. So, for [tex]f(x)[/tex]:

REFLEXION IN THE X-AXIS:

[tex]h(x)=-f(x)[/tex]

REFLEXION IN THE Y-AXIS:

[tex]h(x)=f(-x)[/tex]

d. Sin(x)=-sin(x)

False by the same explanation as b.

The correct statement about the function y=sin(x) is that Reflection over either the x-axis or y-axis will change the graph. Therefore, option C is the correct answer.

The statement regarding the function y=sin(x) which is true is that reflection over either the x-axis or y-axis will change the graph.

This is because the sine function is an odd function, meaning that it has rotational symmetry about the origin. A characteristic of odd functions is that they satisfy the identity y(-x) = -y(x), not y(-x) = y(x), which describes an even function.

Therefore, the assumption Sin(x)=Sin(-x) would be incorrect, as it does not reflect the odd nature of the sine function. Thus, the correct answer is c. Reflection over either the x-axis or y-axis will change the graph.

A computer system uses passwords that contain exactly 7 characters, and each character is 1 of the 26 lowercase letters (a–z) or 26 uppercase letters (A–Z) or 10 integers (0–9). Let Ω denote the set of all possible passwords, and let A and B denote the events that consist of passwords with only letters or only integers, respectively. Determine the probability that a password contains all lowercase letters given that it contains only letters. Report the answer to 3 decimal places.

Answers

Answer:

0,008 or 0,8%

Step-by-step explanation:

To calculate the probability the selected password is made out only of lower-case letters, if it's only letters, we have first to find out how many passwords could be formed with only letters and with only lower-case letters.

For lowercase letters, we can make this many passwords, since for each of the 7  characters, we can pick among 26 lowercase letters:

NLL = 26 * 26 * 26 * 26 * 26 * 26 * 26

In the same fashion, for the number of passwords consisting only of letters, we can pick among 52 letters for each each character (26 lower-case, 26 upper-case):

NOL = 52 * 52 * 52 * 52 * 52 * 52 * 52

We can rewrite NOL differently to ease our calculations:

NOL = (2 * 26) * (2 * 26) * (2 * 26) * (2 * 26) * (2 * 26) * (2 * 26) * (2 * 26)

or

NOL = 26 * 26 * 26 * 26 * 26 * 26 * 26 * 2 * 2 * 2 * 2 * 2 * 2 * 2

Now we have to find out the probability a password containing only letters (NOL) is a password containing only lowercase letters (NLL).  So, we divide NLL by NOL:

[tex]\frac{NLL}{NOL} = \frac{26 * 26 * 26 * 26 * 26 * 26 * 26}{26 * 26 * 26 * 26 * 26 * 26 * 26 * 2 * 2 * 2 * 2 * 2 * 2 * 2}  = \frac{1}{2 * 2 * 2 * 2 * 2 * 2 * 2} = \frac{1}{2^{7} }[/tex]

The probability is thus 1/2^7 or 1/128 or 0,0078125

Which we are asked to round to 3 decimals... so 0,008 or 0,8%

From a survey taken several years ago, the starting salaries of individuals with an undergraduate degree from Business Schools are normally distributed with a mean of $40,500 and a standard deviation of $4,500.What is the probability that a randomly selected individual with an undergraduate business degree will get a starting salary of at least $36,000.00? (Round your answer to 4 decimal places.)

Answers

Answer: 0.8413

Step-by-step explanation:

Given: Mean : [tex]\mu=\$40,500[/tex]

Standard deviation : [tex]\sigma = \$4,500[/tex]

The formula to calculate z-score is given by :_

[tex]z=\dfrac{x-\mu}{\sigma}[/tex]

For x= $36,000.00, we have

[tex]z=\dfrac{36000-40500}{4500}=-1[/tex]

The P-value = [tex]P(z\geq-1)=1-P(z<-1)=1-0.1586553=0.8413447\approx0.8413[/tex]

Hence, the probability that a randomly selected individual with an undergraduate business degree will get a starting salary of at least $36,000.00 = 0.8413

The probability of a randomly selected individual with an undergraduate business degree having a starting salary of at least $36,000, based on the given normal distribution with a mean of $40,500 and a standard deviation of $4,500, is approximately 0.8413 or 84.13%.

The question asks us to find the probability that a randomly selected individual with an undergraduate business degree will have a starting salary of at least $36,000.00, given that the mean starting salary is $40,500 with a standard deviation of $4,500. This problem can be solved using the properties of the normal distribution.

First, we calculate the z-score, which is the number of standard deviations away from the mean:

Z = (X - μ) / σ

Where X is the salary in question ($36,000), μ is the mean ($40,500), and σ is the standard deviation ($4,500). Plugging in the values:

Z = ($36,000 - $40,500) / $4,500 = -1

The next step is to look up this z-score in a standard normal distribution table or use a calculator with a standard normal distribution function to find the area to the right of this z-score. This area represents the probability we are looking for. Let's assume we found this area to be approximately 0.8413.

Therefore, the probability that a randomly selected individual with an undergraduate business degree will have a starting salary of at least $36,000 is about 0.8413 or 84.13%.

A ball is thrown at an initial height of 7 feet with an initial upward velocity at 27 ft/s. The balls height h (in feet) after t seconds is give by the following. h- 7 27t -16t^2 Find the values of t if the balls height is 17ft. Round your answer(s) to the nearest hundredth

Answers

Answer:

The height of ball is 17 ft at t=0.55 and t=1.14.

Step-by-step explanation:

The general projectile motion is defined as

[tex]y=-16t^2+vt+y_0[/tex]

Where, v is initial velocity and y₀ is initial height.

It is given that the initial height is 7 and the initial upward velocity is 27.

Substitute v=27 and y₀=7 in the above equation to find the model for height of the ball.

[tex]h(t)=-16t^2+27t+7[/tex]

The height of ball is 17 ft. Put h(t)=17.

[tex]17=-16t^2+27t+7[/tex]

[tex]0=-16t^2+27t-10[/tex]

On solving this equation using graphing calculator we get

[tex]t=0.549,1.139[/tex]

[tex]t\approx 0.55,1.14[/tex]

Therefore the height of ball is 17 ft at t=0.55 and t=1.14.

For waht values of x do the vectors -1,0,-1), (2,1,2), (1,1, x) form a basis for R3?

Answers

Answer:

The values of x for which the given vectors are basis for R³ is:

                        [tex]x\neq 1[/tex]

Step-by-step explanation:

We know that for a set of vectors are linearly independent if the matrix formed by these set of vectors is non-singular i.e. the determinant of the matrix formed by these vectors is non-zero.

We are given three vectors as:

(-1,0,-1), (2,1,2), (1,1, x)

The matrix formed by these vectors is:

[tex]\left[\begin{array}{ccc}-1&2&1\\0&1&1\\-1&2&x\end{array}\right][/tex]

Now, the determinant of this matrix is:

[tex]\begin{vmatrix}-1 &2 & 1\\ 0& 1 & 1\\ -1 & 2 & x\end{vmatrix}=-1(x-2)-2(1)+1\\\\\\\begin{vmatrix}-1 &2 & 1\\ 0& 1 & 1\\ -1 & 2 & x\end{vmatrix}=-x+2-2+1\\\\\\\begin{vmatrix}-1 &2 & 1\\ 0& 1 & 1\\ -1 & 2 & x\end{vmatrix}=-x+1[/tex]

Hence,

[tex]-x+1\neq 0\\\\\\i.e.\\\\\\x\neq 1[/tex]

At a certain school, intro to economics and intro to calculus meet at the same time, so it is impossible for a student take both classes. If the probability that a student takes intro to economics is 0.57, and the probability that a student takes intro to calculus 0.17, what is the probability that a student takes intro to economics or into to calculus?

Answers

Answer:

  0.74

Step-by-step explanation:

P(A∪B) = P(A) + P(B) - P(A∩B) = 0.57 + 0.17 - 0

P(A∪B) = 0.74

The probability of A∩B is zero because the classes are mutually exclusive.

3. Given the differential equation y"+y= 0 and the set of two functions sint-cost, sint + cost, show that this a fundamental set of functions for the equation, and note the interval(s) over which this is true. wken (osxsihx | Cos sint

Answers

Answer with explanation:

Given the differential equation

y''+y=0

The two function let

[tex]y_1= sint -cost[/tex]

[tex]y_2=sint+ cost[/tex]

Differentiate [tex]y_1 and y_2[/tex]

Then we get

[tex]y'_1= cost+sint[/tex]

[tex]y'_2=cost-sint[/tex]

Because [tex]\frac{\mathrm{d} sinx}{\mathrm{d} x} = cosx[/tex]

[tex]\frac{\mathrm{d}cosx }{\mathrm{d}x}= -sinx[/tex]

We find wronskin to prove that the function  is independent/ fundamental function.

w(x)=[tex]\begin{vmatrix} y_1&y_2\\y'_1&y'_2\end{vmatrix}[/tex]

[tex]w(x)=\begin{vmatrix}sint-cost&sint+cost\\cost+sint&cost-sint\end{vmatrix}[/tex]

[tex]w(x)=(sint-cost)(cost-sint)- (sint+cost)(cost+sint)[/tex]

[tex]w(x)=sintcost-sin^2t-cos^2t+sintcost-sintcost-sin^2t-cos^2t-sintcost[/tex]

[tex]w(x)=-sin^2t-cos^2t[/tex]    

[tex]sin^2t+cos^2t=1[/tex]

[tex]w(x)=-2\neq0[/tex]

Hence, the given two function are fundamental set of function on R.

y is 4 less than the product of 5 and x


























Answers

y is (replace "is" with an equal sign) 4 less (replace with subtraction sign) than the product (multiply 5 and x) of 5 and x

y = 5x - 4

The reason the answer is like this ^^^ instead of y = 4 - 5x is because for this to be true it would have to say y is 5x less then 4

Hope this helped!

~Just a girl in love with Shawn Mendes

Answer:

y=5x-4

Step-by-step explanation:

Question about: ⇒ algebraic expression

Y: ⇒ Symbol into letters

is: ⇒ equal sign

less than: ⇒ <

product: ⇒ multiply

y=5x-4 is the correct answer.

I hope this helps you, and have a wonderful day!

simplify. x^2-3x-18/x+3

Answers

The simplified value is (x  - 6)

How to simplify the given expressions?

[tex]\frac{x^{2} -3x-18}{x+3}\\ = \frac{x^{2} -6x + 3x - 18}{x+3} \\=\frac{x(x-6) +3(x-6)}{x+3}\\ =\frac{(x+3)(x-6)}{x+3}\\ = x - 6[/tex]

So the simplified value is (x  - 6)

Find more details about "Simplifications" here: https://brainly.com/question/4344214

#SPJ2

To simplify the rational expression x^2 - 3x - 18 / x + 3, factor the numerator and cancel out the common factor (x + 3). The simplified form is x - 6.

Simplifying the Rational Expression

To simplify the expression
x² - 3x - 18 / x + 3, follow these steps:

First, factor the numerator, which is a quadratic expression. To factor x² - 3x - 18, find two numbers that multiply to -18 and add up to -3. These numbers are 3 and -6.So, we can rewrite the numerator as (x - 6)(x + 3).Thus, the expression becomes:

(x - 6)(x + 3) / x + 3.

Next, cancel the common factor (x + 3):

(x - 6) (x + 3) / (x + 3) = x - 6

So, the simplified form of the expression is x - 6. Note that this simplification is valid for all values of x except -3, as the denominator would be zero.

What is the Common Factor

3t^5s − 15t^2s^3

Answers

Answer:

3t^2s

Step-by-step explanation:

15/3=5

t^5s/t^2s = t^3

t^2s^3/t^2s = s^2

For this case we have by definition, that a polynomial has a common factor when the same quantity, either number or letter, is found in all the terms of the polynomial.

We have the following expression:

[tex]3t ^ 5s-15t ^ 2s ^ 3[/tex]

So we have to:

[tex]3t ^ 2s[/tex] is the lowest common term in the terms of the expression:

[tex]3t ^ 2s (t ^ 3-5s ^ 2)[/tex]

Answer:

[tex]3t ^ 2s[/tex]

HELP PLEASEEE, I REALLY DO NOT UNDERSTAND THESE QUESTIONS. THANK YOU HELP IS VERY MUCH APPRECIATED!!!
5) The mean salary of 5 employees is $40300. The median is $38500. The lowest paid employee's salary is $32000. If the lowest paid employee gets a $3100 raise, then ...


a) What is the new mean?

New Mean = $



b) What is the new median?

New Median = $

Answers

Answer:

a) $40920

b) $38500

Step-by-step explanation:

Given:

5 employees,

Mean = $40300

Median = $38500

Min = $32000

If he lowest paid employee gets a $3100 raise, then his salary becomes

$32000+$3100=$35100

a) If the mean was $40300, then the sum of 5 salaries is

[tex]\$40300\cdot 5=\$201500[/tex]

After raising the lowest salary the sum becomes

[tex]\$201500+\$3100=\$204600[/tex]

and new mean is

[tex]\dfrac{\$204600}{5}=\$40920[/tex]

b) The  lowest salary becomes $35100. It is still smaller than the median, so the new median is the same as the old one.

New median = $38500

Help Algebra!!


10. To solve a system of equations using the matrix method, use elementary row operations to transform the augmented matrix into one with _______. Then, proceed back to substitute.


A. zeros in its final column


B. an inverse


C. zeros below the diagonal


D. Gaussian elimination


Answers

Answer:

  C. zeros below the diagonal

Step-by-step explanation:

Upper echelon form (zeros below the diagonal) corresponds to a system of equations that has one equation in one variable, one equation in two variables, and additional equations in additional variables adding one variable at a time.

The single equation in a single variable is easily solved, and that result can be substituted into the equation with two variables (one of which is the one just found) to find one more variable's value. This back-substitution proceeds until all variable values have been found.

The process of producing such a matrix is called Gaussian Elimination.

__

The back-substitution process effectively makes the matrix be an identity matrix (diagonal = ones; zeros elsewhere) and the added column be the solution to the system of equations.

Final answer:

To solve a system of equations using the matrix method, you transform the augmented matrix to have zeros below the diagonal through Gaussian elimination. Then, you substitute back into the equations to find the solution.

Explanation:

To solve a system of equations using the matrix method, you use elementary row operations to transform the augmented matrix into one with zeros below the diagonal. This is achieved through a method called Gaussian elimination. The goal is to reduce the matrix to its row-echelon form, which leaves zeros below the diagonal. After this reduction, you can then proceed to substitute back into the equations to find the solution.

For example, let's take the system of equations:
x+2y=7
3x-4y=11
This can be represented as an augmented matrix:
[1 2 | 7]
[3 -4 | 11]
Using Gaussian elimination, we can eliminate the '3' below the diagonal by subtracting 3x the first row from the second, getting you:
[1 2 | 7]
[0 -10 | -10]
By substituting, we then find the solutions for the system of equations.

Learn more about Matrix Method here:

https://brainly.com/question/31978592

#SPJ2

What is the mass, in grams, of the object being measured in the triple beam balance shown below?

Snapshot of a triple beam balance. The large slider is at 100 g, the medium slider is at 0 g, and the small slider is at 2.5 g.

Answers

Answer:

  102.5 g

Step-by-step explanation:

The mass is the sum of the values indicated by the sliders:

  100 g + 0 g + 2.5 g = 102.5 g

Answer:

The mass, in grams, of the object being measured in the triple beam balance shown below is:

                               102.5 g

Step-by-step explanation:

Triple Beam balance--

It is a instrument which is used to measure the mass of an object.

The advantage of using this device is that it measures the mass of an object precisely.

It has three counterweights in it.

One is of 100 gram, other is of 10 gram and the last is of 1 gram.

In order to find the mass of an object we add the weights in all the three sections.

The large slider is at 100 g, the medium slider is at 0 g, and the small slider is at 2.5 g.

                    100 g+0 g+2.5 g=102.5 g

Maria needs to know How much Money $ to have with her when She Goes to her favorite Show Store ... How Much money Should Bring to buy a pair of Shoes ?? ? If, the Original price is $ 80 and there is a discount of 20% and the Sale will only last for one week ... ​

Answers

Answer: $64

Step-by-step explanation:

Set up is/of ratio. See photo attached. (:

The sample space listing the eight simple events that are possible when a couple has three children is​ {bbb, bbg,​ bgb, bgg,​ gbb, gbg,​ ggb, ggg}. After identifying the sample space for a couple having four​ children, find the probability of getting (one girl and three boys) in any order right parenthesis.

Answers

[tex]|\Omega|=2^4=16\\|A|=4\\\\P(A)=\dfrac{4}{16}=\dfrac{1}{4}[/tex]

You are given three white​ balls, one red​ ball, and two identical boxes. You are asked to distribute the balls in the boxes in any way you like. You then are asked to select a box​ (after the boxes have been​ shuffled) and to pick a ball at random from that box. If the ball is red you win a prize. How should you distribute the balls in the boxes to maximize your chances of​ winning? Justify your reasoning.

Answers

Put all the white balls in one box and the red ball in the other so you have a 50% chance of winning if you put 1 red ball and a white now you have a 25% chance cause you have a 50% chance in choosing the right box then you have to chose the right ball which would be 50%

[tex]\text{I was eating cookies and had some thoughts. If I wanted to cut out exactly }[/tex][tex] \frac{1}{3} [/tex]of the cookie to share with someone, how far from one side would I have to make a straight cut to get that exact amount? How far would I have to cut if I wanted to cut off[tex] \frac{1}{n} [/tex][tex]\text{ of the cookie?}[/tex]

[tex]\text{Basically, the question is, find the value of }a\text{ given only n, and r}[/tex]

[tex]\text{One way of finding this, is by finding the area of the shaded reigon, Q in terms of}[/tex]
[tex]\text{r, a, and b, and equating it to the area of the fraction of the cookie then solving for a.}[/tex]

[tex]\text{In math, this means solving } \frac{1}{n}\pi r^2=Q \text{ for }f(r,n)=a.[/tex]

[tex]\text{From the diagram, we can see that }r=a+b[/tex]

[tex]\text{Eventually, by 2 different means, I found 2 equations that, if solved, would give the}[/tex][tex]\text{ relationship between r, n, and a.}[/tex][tex]\text{They are as follows:}[/tex]

[tex]\text{1. }\frac{1}{n}\pi r=r\theta-bsin(\theta) \text{ where }\theta=cos^{-1}(\frac{b}{r})[/tex]

[tex]\text{2. }\frac{1}{n}\pi=\theta-sin(2\theta)\text{ where }\theta=cos^{-1}(\frac{b}{r})[/tex]

[tex]\text{These 2 equations are equivalent, but annoying to solve.}[/tex]

[tex]\text{To claim these points, please solve for a in terms of r and n, showing all work.}[/tex]
[tex]\text{I would like an analytic solution if possible.}[\tex]
[tex]\text{All incorrect, spam, or no-work solutions will be reported.}[/tex]

Answers

In the attachement, there is what I came up with so far. I think that finding 'a' is non-trivial, if possible at all.

[tex]A_c[/tex] - the area of a circle

[tex]A_{cs}[/tex] - the area of a circular segment

Answer:

- the area of a circle

- the area of a circular segment

F(x)=3x+4. Determine the value of F (X) when X equals -1

Answers

ANSWER

The value of this function at x=-1 is 1

EXPLANATION

The given function is

[tex]f(x) = 3x + 4[/tex]

We want to find the value of this function at x=-1.

We substitute x=-1 into the function to obtain:

[tex]f( - 1) = 3( - 1)+ 4[/tex]

We multiply out to obtain:

[tex]f( - 1) = - 3+ 4[/tex]

[tex]f( - 1) = 1[/tex]

Therefore the value of this function at x=-1 is 1.

Answer:  [tex]f(-1)=1[/tex]

Step-by-step explanation:

Given the linear function f(x):

[tex]f(x)=3x+4[/tex]

By definition. a relation is a function if each input value has only one output value. In this case you need to find the output value for the input value [tex]x=-1[/tex]. In order to do this, you need to substitute this value of the variable "x" into the linear function given.

Then:

When [tex]x=-1[/tex]:

[tex]f(-1)=3(-1)+4[/tex]

Remember the multiplication of signs:

[tex](+)(-)=-\\(+)(+)=+\\(-)(-)=+[/tex]

Then, the value of f(x) when [tex]x=-1[/tex] is:

 [tex]f(-1)=-3+4[/tex]

 [tex]f(-1)=1[/tex]

What is the maxima minima or zero for this graph???

Answers

Maximum is the highest a graph can reach. In this case the graph continues forever therefore the maximum is:

infinity or ∞

The minimum is the lowest place the graph reaches. In this case it would be:

-6

The zeros are where the graph intersects the x axis. In this case it would have two zeros, which are:

(-3, 0) and (0.5, 0)

Hope this helped!

~Just a girl in love with Shawn Mendes

A sample is selected from a population with a mean of μ = 40 and a standard deviation of σ = 8. a. If the sample has n = 4 scores, what is the expected value of M and the standard error of M? b. If the sample has n = 16 scores, what is the expected value of M and the standard error of M? Gravetter, Frederick J. Statistics for The Behavioral Sciences (p. 221). Cengage Learning. Kindle Edition.

Answers

Answer:

a) The expected value of M = 40

The standard error for M = 4

b) The expected value of M = 40

The standard error for M = 2

Step-by-step explanation:

* Lets revise some definition to solve the problem

- The mean of the distribution of sample means is called the expected

  value of M

- It is equal to the population mean μ

- The standard deviation of the distribution of sample means is called

  the standard error of M

- The rule of standard error is σM = σ/√n , where σ is the standard

  deviation and n is the size of the sample

* lets solve the problem

- A sample is selected from a population

∵ The mean of the population μ = 40

∵ The standard deviation σ = 8

a) The sample has n = 4 scores

∵ The expected value of M = μ

∵ μ = 40

∴ The expected value of M = 40

∵ The standard error of M = σ/√n

∵ σ = 8 and n = 4

∴ σM = 8/√4 = 8/2 = 4

∴ The standard error for M = 4

b) The sample has n = 16 scores

∵ The expected value of M = μ

∵ μ = 40

∴ The expected value of M = 40

∵ The standard error of M = σ/√n

∵ σ = 8 and n = 16

∴ σM = 8/√16 = 8/4 = 2

∴ The standard error for M = 2

When the sample has n = 4 scores then the expected value of M is 40 and the standard error of M is 4.

When the sample has n = 16 scores then the expected value of M is 40 and the standard error of M is 2.

Given

A sample is selected from a population with a mean of μ = 40 and a standard deviation of σ = 8. a. If the sample has n = 4 scores.

What is the expected value of M?

The mean of the distribution of sample means is called the expected value of M.

The standard deviation of the distribution of sample means is called the standard error of M.

1. The sample has n = 4 scores

The expected value of M = μ

The expected value of M = 40

The standard error of M is;

[tex]\rm Standard \ error=\dfrac{\sigma}{\sqrt{n} }\\\\ \sigma = 8 \ and \ n = 4}\\\\ Standard \ error=\dfrac{8}{\sqrt{4}}\\\\ Standard \ error=\dfrac{8}{2}\\\\ Standard \ error=4[/tex]

The standard error for M = 4

2.  1. The sample has n = 16 scores

The expected value of M = μ

The expected value of M = 40

The standard error of M is;

[tex]\rm Standard \ error=\dfrac{\sigma}{\sqrt{n} }\\\\ \sigma = 8 \ and \ n = 16}\\\\ Standard \ error=\dfrac{8}{\sqrt{16}}\\\\ Standard \ error=\dfrac{8}{4}\\\\ Standard \ error=2[/tex]

The standard error for M = 2

To know more about standard deviation click the link given below.

https://brainly.com/question/10984586

proof true or false: For all integers a,b,and c,if ab|c then a|c and b|c

Answers

Answer with explanation:

It is given that for three integers , a, b and c, if

              [tex]\frac{ab}{c}\rightarrow then, \frac{a}{c} \text{or} \frac{b}{c}[/tex]

Since , a b is divisible by c , following are the possibilities

1.→ a and b are prime integers .Then , c will be prime number either equal to a or b.

2.→a and b are not prime integers ,then any of the factors of a or b will be equal to c.For example:

 ⇒a=m × n

 b=p × q× c

or,

⇒a=u×v×c

b=s×t

So, whatever the integral values taken by a, and b, if [tex]\frac{ab}{c}[/tex] then either of  [tex]\frac{a}{c} \text{or} \frac{b}{c}[/tex] is true.

Twenty switches in an office computer network are to be connected so that each switch has a direct connection to exactly three other switches. How many connections will be necessary?

Answers

Answer:

  30 connections

Step-by-step explanation:

20 switches with 3 connections each will have a total of 20×3 = 60 connections. That counts each connecting link twice, so only 30 connecting links are required.

Answer:

30 Connections!

Step-by-step explanation:

I did this on AoPs :)

Find the general solution of the given differential equation. x dy dx − y = x2 sin(x) Give the largest interval over which the general solution is defined. (Think about the implications of any singular points. Enter your answer using interval notation.

Answers

[tex]x\dfrac{\mathrm dy}{\mathrm dx}-y=x^2\sin x[/tex]

Divide both sides by [tex]x^2[/tex]. In doing so, we force any possible solutions to exist on either [tex](-\infty,0)[/tex] or [tex]\boxed{(0,\infty)}[/tex] (the "positive" interval in such a situation is usually taken over the "negative" one) because [tex]x[/tex] cannot be 0 in order for us to do this.

[tex]\dfrac1x\dfrac{\mathrm dy}{\mathrm dx}-\dfrac1{x^2}y=\sin x[/tex]

Condense the left side as the derivative of a product, then integrate both sides and solve for [tex]y[/tex]:

[tex]\dfrac{\mathrm d}{\mathrm dx}\left[\dfrac yx\right]=\sin x[/tex]

[tex]\dfrac yx=\displaystyle\int\sin x\,\mathrm dx[/tex]

[tex]\boxed{y=Cx-x\cos x}[/tex]

The general solution of a differential equation is to write y as a function of x.

The general solution of [tex]x \frac{dy}{dx} - y = x^2 \sin(x)[/tex] is [tex]y = -x\cos(x) + cx[/tex].The interval of the solution is [tex](0, \infty)[/tex]

Given

[tex]x \frac{dy}{dx} - y = x^2 \sin(x)[/tex]

Divide through by x

[tex]\frac{x}{x} \frac{dy}{dx} -\frac{y}{x} = \frac{x^2}{x} \sin(x)[/tex]

[tex]\frac{dy}{dx} -\frac{y}{x} = x \sin(x)[/tex]

Let P be function of x. Such that:

[tex]P(x) = -\frac 1x[/tex]

So, we have:

[tex]\frac{dy}{dx} +yP(x) = x\sin(x)[/tex]

Calculate the integrating factor I(x).

So, we have:

[tex]I(x) = e^{\int P(x) dx[/tex]

Substitute [tex]P(x) = -\frac 1x[/tex]

[tex]I(x) = e^{\int-\frac 1x dx[/tex]

Rewrite as:

[tex]I(x) = e^{-\int\frac 1x dx[/tex]

Integrate

[tex]I(x) = e^{-\ln(x)[/tex]

[tex]I(x) = \frac 1x[/tex]

So, we have:

[tex]\frac{dy}{dx} -\frac{y}{x} = x \sin(x)[/tex]

[tex][\frac{dy}{dx} -\frac{y}{x}] \frac 1x = [x \sin(x)] \frac 1x[/tex]

[tex][\frac{dy}{dx} -\frac{y}{x}] \frac 1x =\sin(x)[/tex]

Introduce [tex]I(x) = \frac 1x[/tex].

So, we have:

[tex]\frac{d}{dx}(\frac yx) = \sin(x)[/tex]

Multiply both sides by dx

[tex]d(\frac yx) = \sin(x)\ dx[/tex]

Integrate with respect to x

[tex]\frac yx = -\cos(x) + c[/tex]

Multiply through by x

[tex]y = -x\cos(x) + cx[/tex]

So, the general solution is: [tex]y = -x\cos(x) + cx[/tex], and the interval is [tex](0, \infty)[/tex]

Read more about general solution of a differential equation at:

https://brainly.com/question/4537000

The number of typing errors made by a typist has a Poisson distribution with an average of two errors per page. If more than two errors appear on a given page, the typist must retype the whole page. What is the probability that a randomly selected page does not need to be retyped? (Round your answer to three decimal places.)

Answers

Answer: 0.6767

Step-by-step explanation:

Given : Mean =[tex]\lambda=2[/tex] errors  per page

Let X be the number of errors in a particular page.

The formula to calculate the Poisson distribution is given by :_

[tex]P(X=x)=\dfrac{e^{-\lambda}\lambda^x}{x!}[/tex]

Now, the probability that a randomly selected page does not need to be retyped is given by :-

[tex]P(X\leq2)=P(0)+P(1)+P(2)\\\\=(\dfrac{e^{-2}2^0}{0!}+\dfrac{e^{-2}2^1}{1!}+\dfrac{e^{-2}2^2}{2!})\\\\=0.135335283237+0.270670566473+0.270670566473\\\\=0.676676416183\approx0.6767[/tex]

Hence, the required probability :- 0.6767

hi i’m not sure how to do question 20 if u could explain how to do it that’d b great !!

Answers

Answer:

  A)  -2

Step-by-step explanation:

The form is indeterminate at x=0, so L'Hopital's rule applies. The resulting form is also indeterminate at x=0, so a second application is required.

Let f(x) = x·sin(x); g(x) = cos(x) -1

Then f'(x) = sin(x) +x·cos(x), and g'(x) = -sin(x).

We still have f'(0)/g'(0) = 0/0 . . . . . indeterminate.

__

Differentiating numerator and denominator a second time gives ...

  f''(x) = 2cos(x) -sin(x)

  g''(x) = -cos(x)

Then f''(0)/g''(0) = 2/-1 = -2

_____

I like to start by graphing the expression to see if that is informative as to what the limit should be. The graph suggests the limit is -2, as we found.

Solve log x=2. A. 2 B. 20 C. 100 D. 1,000

Answers

Answer:

100

Step-by-step explanation:

The value of the given logarithm is 100.

What is logarithm?

A logarithm is the power to which a number must be raised in order to get some other number.

Given that, log x = 2,

We will solve a logarithmic equation of x  by changing it to exponential form.

Now, the logarithmic equation is log₁₀x = 2

Since, we know that, logₐb = x then b = aˣ

Therefore, log₁₀x = 2

x = 10²

x = 100

Hence,  the value of the given logarithm is 100.

Learn more about logarithm, click;

https://brainly.com/question/30085872

#SPJ5

y" +2y' +17y=0; y(0)=3, y'(0)=17

Answers

Answer:

The solution is [tex]y(t)=e^{-t}(\cos 32t + (\frac{5}{8}) \sin 32t)[/tex]

Step-by-step explanation:

We need to find the solution of [tex]y''+2y'+17y=0[/tex] with

condition [tex]y(0)=3,\ y'(0)=17[/tex]

This is a homogeneous equation with characteristic polynomial

[tex]r^{2}+2r+17=0[/tex]

using quadratic formula [tex]x=\frac{-b\pm \sqrt{b^{2}-4ac}}{2a}[/tex]

[tex]r=\frac{-2\pm \sqrt{2^{2}-4(1)(17)}}{2(1)}[/tex]

[tex]r=\frac{-2\pm \sqrt{4-68}}{2}[/tex]

[tex]r=\frac{-2\pm \sqrt{-64}}{2}[/tex]

[tex]r=\frac{-2\pm 64i}{2}[/tex]

[tex]r=-1 \pm 32i[/tex]

The general solution for eigen value [tex]a \pm ib[/tex] is

[tex]y(t)=e^{at}(A \cos bt + B \sin bt)[/tex]

[tex]y(t)=e^{-t}(A \cos 32t + B \sin 32t)[/tex]

Differentiate above with respect to 't'

[tex]y'(t)=-e^{-t}(A \cos 32t + B \sin 32t) + e^{-t}(-32A \sin 32t + 32B \cos 32t)[/tex]

Since, y(0)=3

[tex]y(0)=e^{0}(A \cos(0) + B \sin(0))[/tex]

[tex]3=(A \cos(0) +0)[/tex]

so, A=1

Since, y'(0)=17

[tex]y'(0)=-e^{0}(3 \cos(0) + B \sin(0)) + e^{0}(-32(3) \sin(0) + 32B \cos (0))[/tex]

[tex]17=-(3 \cos(0)) + (0 + 32B \cos (0))[/tex]

[tex]17=-3 + 32B[/tex]

add both the sides by 3,

[tex]17+3 = 32B[/tex]

[tex]20= 32B[/tex]

divide both the sides, by 32,

[tex]\frac{20}{32}= B[/tex]

[tex]\frac{5}{8}= B[/tex]

Put the value of constants in [tex]y(t)=e^{-t}(A \cos 32t + B \sin 32t)[/tex]

[tex]y(t)=e^{-t}((1) \cos 32t + (\frac{5}{8}) \sin 32t)[/tex]

Therefore, the solution is [tex]y(t)=e^{-t}(\cos 32t + (\frac{5}{8}) \sin 32t)[/tex]

The value of X is??​

Answers

for this case we have that by definition, the sum of the internal angles of a traingule is 180 degrees.

In addition, the angle "R" of the triangle is given by:

[tex]R = 180-45x[/tex]

So, we have to:

[tex](180-45x) + 25x + (57 + x) = 180\\180-45x + 25x + 57 + x = 180\\-45x + 25x + 57 + x = 0\\-45x + 25x + x = -57\\-19x = -57\\x = \frac {57} {19}\\x = 3[/tex]

Answer:

[tex]x = 3[/tex]

13.48x - 200 < 256.12​

Answers

Answer:

x < 33.84

Step-by-step explanation:

we have

13.48x-200 < 256.12

Solve for x

Adds 200 both sides

13.48x-200 +200 < 256.12+200

13.48x < 456.12

Divide by 13.48 both sides

13.48x/13.48 < 456.12/13.48

x < 33.84

The solution is the interval ----> (-∞, 33.84)

All real numbers less than 33.84

What is the area of this composite figure?

Answers

Answer:

88 ft²

Step-by-step explanation:

Area of larger square

10 × 8 = 80

10 × 8 because 10 is the length and 8 because the 6 and 2 rectangle is missing so it wouldn't be 10 × 10

4 × 2 = 8

4 × 2 = 8 because we need to work out the area of the smaller rectangle

80 + 8 = 88

54 percent off my phone
Other Questions
7. Show all work to identify the discontinuity and zero of the function f of x equals 5 x over quantity x squared minus 25.8. The aquarium has 6 fewer yellow fish than green fish. 40 percent of the fish are yellow. How many green fish are in the aquarium? Show your work. (t9)-8 what is the simplify expression Senator Joseph McCarthy gained popularity and power by You just finished paving a rectangular driveway measuring 75 feet by 20 feet. You charged the customer $1,000. After deducting the expenses shown below, how much profit did your company make on this job? Running the state is a challenging task so is managing the home. Become the ChiefMinister of your home for a day and try running it. You can begin with making a list ofgrocery to fixing menu, getting the clothes washed and attending the needs of parents,grandparents and siblings. At the end of the day, write a diary entry descriing yourexperiences. A striking tool is a basic hand tool with what logical prediction can be made from this passage? Describe connections between the Declaration of Independence and the third principle, natural and individual rights. be sure to include a quote from the declaration of independence Find the cube roots of 27(cos 279 + i sin 279). Bismuth-210 is an isotope that radioactively decays by about 13% each day, meaning 13% of the remaining Bismuth-210 transforms into another atom (polonium-210 in this case) each day. If you begin with 233 mg of Bismuth-210, how much remains after 8 days? Under the Articles of Confederation, what power did the national Confederation Congress have?the power to taxthe power to enforce foreign treatiesthe power to enforce commercial trade agreementsthe power to create land ordinances The House of Burgesses was the main tobacco company of the Virginia colony. Compare the rates of change of the following items. A. The rate of change of item I is greater than the rate of change of item II. B. The rate of change of item II is greater than the rate of change of item I. C. The rate of change of item I is equal to the rate of change of item II. Which quantities is proportional to 2613? Factor p 2 + 18p + 32.(p+ 4)(p + 8)(P + 2)p+ 16)(P + 16)2 phillis wheatley describes misery in her poem. What caused this feeling Write 12 more than r as an expression 11 pt please help me Select the statement that does NOT use verbal irony. I love a fresh rain after getting the car washed. You should be more like him and leave a mess at the table for others to clean up. Leah is such a great singer even the dogs join in. Jason would love to play basketball. Which table of values could be generated by the equation 4y2x=16 Emily went to a local shop to purchase some round rugs. Each rug has a radius of 3 feet. She istrying to cover as much of the floor of her 18 foot by 20 foot living room as possible withoutany overlap of the rugs. How much of the bare floor will be visible around the rugs?A. 20.76 square feetB. 254.47 square feetC. 9 square feetD. 105.5 square feet