There are 40 students in an elementary statistics class. On the basis of years of experience, the instructor knows that the time needed to grade a randomly chosen first examination paper is a random variable with an expected value of 6 min and a standard deviation of 6 min.If a grading times are independent and the instructor begins grading at 6:50 P.M. and grades continuously, the (approximate probability that he is through grading before the 11:00 P.M. TV news begins is probability isIf the sports report begins at 11:10 P.M., the probability that he misses part of the report if he waits until grading is done before turning on the TV is

Answer:

  2 cm and 6 cm

Step-by-step explanation:

The product of the dimensions must be 12 cm². (All answer choices meet that requirement.)

Opposite sides of a rectangle are the same length, so the sum of the two dimensions must be half the perimeter, 8 cm. The sums of the answer choices are ...

Only the first answer choice meets the requirement for a perimeter of 16 cm. The dimensions could be 2 cm and 6 cm.

6

×

2

Explanation:

For the rectangle

Length

=

ℓ

Breadth

=

b

Area is  

12

cm

2

ℓ

b

=

12

Perimeter is  

16

cm

2

(

ℓ

+

b

)

=

16

ℓ

+

b

=

8

Substitute  

b

=

12

ℓ

from first equation

ℓ

+

12

ℓ

=

8

ℓ

2

+

12

=

8

ℓ

ℓ

2

−

8

ℓ

+

12

=

0

Use quadratic formula (

x

=

−

b

±

√

b

2

−

4

a

c

2

a

) to find  

ℓ

ℓ

=

−

(

−

8

)

±

√

(

−

8

)

2

−

(

4

×

1

×

12

)

2

×

1

ℓ

=

8

±

√

16

2

ℓ

=

8

±

4

2

ℓ

1

=

8

+

4

2

=

6

ℓ

2

=

8

−

4

2

=

2

If  

ℓ

1

is taken as length then  

ℓ

2

is the breadth of the rectangle.

Answer:

g(x) = x^2 + 4x + 4

Step-by-step explanation:

In translation of functions, adding a constant to the domain values (x) of a function will move the graph to the left, while subtracting from the input of the function will move the graph to the right.

Given the function;

f(x) = x2 - 6x + 9

a shift 5 units to the left implies that we shall be adding the constant 5 to the x values of the function;

g(x) = f(x+5)

g(x) = (x+5)^2 - 6(x+5) + 9

g(x) = x^2 + 10x + 25 - 6x -30 + 9

g(x) = x^2 + 4x + 4

Answer:

2.9%

Step-by-step explanation:

The problem says the stations are 260 feet apart.  Assuming that this is the horizontal distance between them, then the grade is:

7.5 / 260 × 100% = 2.9%

This is less than the maximum of 3.5%, so it meets the standards.

Check the picture below.

The answer is g(x) = (1/4 x)^2

It has a horizontal stretch of 4. Since it is horizontal it goes inside the parentheses and becomes the reciprocal of 4  which is  1/4

Hope this helped!

~Just a girl in love with Shawn Mendes

Answer:

Cortex layer

Step-by-step explanation:

The fibrous protein core of the hair, formed by elongated cells containing melanin pigment, is the cortex layer

Answer:

The fibrous protein core formed by elongated cells that contains melanin pigment is the cortex.

Answer:

a)

[tex]y=400(2.5)^{x}[/tex]

b)

3,814,698

c)

16.08 weeks

Step-by-step explanation:

a)

The question presented here is similar to a compound interest problem. We are informed that there are 400 rice weevils at the beginning of the study. In a compound interest problem this value would be our Principal.

P = 400

Moreover, the population is expected to grow at a rate of 150% every week. This is equivalent to a rate of interest in a compound interest problem.

r = 150% = 1.5

The compound interest formula is given as;

[tex]A=P(1+r)^{n}[/tex]

We let y be the weevil population in any given week x. The formula that can be used to predict the weevil population is thus;

[tex]y=400(1+1.5)^{x}\\\\y=400(2.5)^{x}[/tex]

b)

The weevil population 10 weeks after the beginning of the study is simply the value of y when x = 10. We substitute x with 10 in the equation obtained from a) above;

[tex]y=400(2.5)^{10}\\\\y=3814697.3[/tex]

Therefore, the weevil population 10 weeks after the beginning of the study is approximately 3,814,698

c)

We are simply required to determine the value of x when y is

1,000,000,000

Substitute y with 1,000,000,000 in the equation obtained in a) above and solve for x;

[tex]1000000000=400(2.5)^{x}\\\\2.5^{x}=2500000\\\\xln(2.5)=ln(2500000)\\\\x=\frac{ln(2500000}{ln(2.5)}=16.0776[/tex]

Answer:

Step-by-step explanation:

The base is defined as x. The height is said to be 3 less than 2x, so is (2x-3).

The formula for the area of a triangle is ...

  A = (1/2)bh

Filling in the given values, we have ...

  17.5 = (1/2)x(2x-3)

  35 = 2x^2 -3x . . . . multiply by 2

  2x^2 -3x -35 = 0 . . . . put in standard form

  (2x +7)(x -5) = 0 . . . . . factor

The base is 5 meters; the height is 2·5-3 = 7 meters.

The base and height of the triangle satisfying the given conditions are approximately 4.3 and 5.6 meters, respectively.

The area of a triangle is given by the formula 1/2 * base * height. Here, the area is 17.5 square meters, the base of the triangle is x, and the height of the triangle is 3 meters less than twice its base, therefore the height is 2x-3. Plugging these values into the formula, we get 17.5 = 1/2 * x * (2x - 3).

To solve this equation for x, first simplify the right-hand side, yielding 17.5 = x*(2x - 3). Multiplying this out gives 17.5 = 2x^2 - 3x. Then, rearrange to get the equation in standard quadratic form, resulting in 2x^2 - 3x - 17.5 = 0.

Through using quadratic formula we can find the solution(s) to be approximately x = 4.3 or x = -2.0. Since a negative value for x ? the base of a triangle ? is not possible, we discard that solution. Thus, the base of the triangle is 4.3 meters, and the height would then be 2*4.3 - 3 = about 5.6 meters.

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Answer:

The solutions of linear equations in the procedure

Step-by-step explanation:

Part 1) we have

x+y=-1 ----> equation A

-6x+2y=14 ----> equation B

Solve the system by elimination

Multiply the equation A by 6 both sides

6*(x+y)=-1*6

6x+6y=-6 -----> equation C

Adds equation C and equation B

6x+6y=-6

-6x+2y=14

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

6y+2y=-6+14

8y=8

y=1

Find the value of x

substitute in the equation A

x+y=-1 ------> x+1=-1 ------> x=-2

The solution is the point (-2,1)

Part 2) we have

-4x+y=-9 -----> equation A

5x+2y=3 ------> equation B

Solve the system by elimination

Multiply the equation A by -2 both sides

-2*(-4x+y)=-9*(-2)

8x-2y=18 ------> equation C

Adds equation B and equation C

5x+2y=3

8x-2y=18

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

5x+8x=3+18

13x=21

x=21/13

Find the value of y

substitute in the equation A

-4x+y=-9 ------> -4(21/13)+y=-9 ----> y=-9+84/13 -----> y=-33/13

The solution is the point (21/13,-33/13)

Part 3) we have

-x+2y=4 ------> equation A

-3x+6y=11 -----> equation B

Multiply the equation A by 3 both sides

3*(-x+2y)=4*3 ------> -3x+6y=12

so

Line A and Line B are parallel lines with different y-intercept

therefore

The system has no solution

Part 4) we have

x-2y=-5 -----> equation A

5x+3y=27 ----> equation B

Solve the system by elimination

Multiply the equation A by -5 both sides

-5*(x-2y)=-5*(-5)

-5x+10y=25 -----> equation C

Adds equation B and equation C

5x+3y=27

-5x+10y=25

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

3y+10y=27+25

13y=52

y=4

Find the value of x

Substitute in the equation A

x-2y=-5 -----> x-2(4)=-5 -----> x=-5+8 ------> x=3

The solution is the point (3,4)

Part 5) we have

6x+3y=-6 ------> equation A

2x+y=-2 ------> equation B

Multiply the equation B by 3 both sides

3*(2x+y)=-2*3

6x+3y=6

so

Line A and Line B is the same line

therefore

The system has infinite solutions

Part 6) we have

-7x+y=1 ------> equation A

14x-7y=28 -----> equation B

Solve the system by elimination

Multiply the equation A by 7 both sides

7*(-7x+y)=1*7

-49x+7y=7 -----> equation C

Adds equation B and equation C

14x-7y=28

-49x+7y=7

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

14x-49x=28+7

-35x=35

x=-1

Find the value of y

substitute in the equation A

-7x+y=1  -----> -7(-1)+y=1 ----> y=1-7 ----> y=-6

The solution is the point (-1,-6)

Answer:

60

Step-by-step explanation:

We have been given the matrix;

[tex]\left[\begin{array}{ccc}5&8\\-5&4\end{array}\right][/tex]

For a 2-by-2 matrix, the determinant is calculated as;

( product of elements in the leading diagonal) - (product of elements in the other diagonal)

determinant = ( 5*4) - (8*-5)

                     = 20 - (-40) = 60

Answer:

c. 60

Step-by-step explanation

math

Answer:

first u should find the radius .radius is half of diameter 12/2=6 so surface area of sphere is 4*3.142*6*6=452.448 square in

Answer:

[tex]|AB|=30[/tex]

Step-by-step explanation:

From the diagram,

AO=OC=16 units, all radii of a circle are equal.

BO=OC+BC

BO=16+18

BO=34

A tangent to a circle will always meet the radius at right angles.

We use the Pythagoras Theorem to obtain:

[tex]|AB|^2+|AO|^2=|BO|^2[/tex]

[tex]|AB|^2+16^2=34^2[/tex]

[tex]|AB|^2+256=1156[/tex]

[tex]|AB|^2=1156-256[/tex]

[tex]|AB|^2=900[/tex]

Take positive square roots to get:

[tex]|AB|=\sqrt{900}[/tex]

[tex]|AB|=30[/tex]

Answer:

Choice B is correct;  (10, 60)

Step-by-step explanation:

For Lisa to make a profit, the function R should assume a value greater than 0;

R > 0

We are to determine the interval of x values for which the above expression will be true.

From the graph, R(x) = 0 when x = 10. As x increases from 10 to 60, the value of R(x) remains positive, that is;

R(x) ≥ 0 for values of x in the interval (10, 60)

The domain that she should use in order to only model selling prices for which she will make a profit is thus;

(10, 60)

Answer:

B

Step-by-step explanation:

In the equation for interest compounding continuously, the A stands for the amount after the compounding is done, the P is the initial amount invested, the e is Euler's number, the r is the rate in decimal form, and the t is the time in years that the money is invested.  Setting up our equation with the given values looks like this:

[tex]A=22,000e^{(.0385)(11)}[/tex]

Multiply the rate with the time to simplify a bit to

[tex]A=22,000e^{.4235}[/tex]

Raise e to the power of .4235 on your calculator (hit 2nd then the ln button to get your e) and get

[tex]A=22,000(1.527297754)[/tex]

Multiply out to get $33600.55, but rounding up gives you B as your answer.

The balance in the account after 11 years is $33,600.6. Thus, the correct option is B.

Theoretically, long-term average interest means that interest is continuously earned on a current account as well as reinvested into the balance to increase future interest earnings.

The equation is given as,

[tex]\rm P=P_o \times e^{rt}[/tex]

The balance in the account after 11 years is calculated as,

[tex]\rm P = \$22,000 \times e^{0.0385\times 11}[/tex]

Simplify the equation, then we have

P = $22,000 x 1.52729

P = $33,600.6

Thus, the correct option is B.

More about the continuous compounding link is given below.

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Answer:

Step-by-step explanation:

The mnemonic SOH CAH TOA reminds you ...

  Sin = Opposite/Hypotenuse

Side DF is opposite the marked angle, and the hypotenuse is EF, so ...

  sin(60°) = (√3)/2 = DF/(14√3) . . . . . to solve, multiply by the denominator

  DF = (√3)/2·(14√3) = 7·3 = 21

__

Likewise,

  Cos = Adjacent/Hypotenuse

Side DE is adjacent to the marked angle, so ...

  cos(60°) = 1/2 = DE/(14√3) . . . . . to solve, multiply by the denominator

  DE = (1/2)(14√3) = 7√3

diameter and height i think

Answer:

they describe diameter and height

26-diameter

34-height

I hope this helps with you

The compound inequality representing the range of possible values for 'x' (side length BC) in the triangle ABC, given that side lengths AB=13 and AC=21, is 8 < x < 34.

In the triangle ABC with side lengths, AB=13, AC=21, and BC=x, we use the triangle inequality theorem which states that the length of a side of a triangle is less than the sum of the lengths of the other two sides and more than the absolute difference between them. Applying this theorem to your specific situation, we get the compound inequality 8 < x < 34. This inequality represents the range of possible values for the side length x is BC.

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For triangle ABC with sides AB = 13, AC = 21, and BC = x, the range of possible values for x is[tex]\( 8 < x < 34 \)[/tex] based on the triangle inequality theorem.

In triangle ABC, the relationship among its side lengths is governed by the triangle inequality theorem, which states that the sum of the lengths of any two sides of a triangle must be greater than the length of the remaining side.

For the given triangle with side lengths AB = 13, AC = 21, and BC = x, we can express this relationship as a compound inequality. Let \[tex]( a \), \( b \), and \( c \)[/tex]  represent the lengths of the sides of the triangle. According to the triangle inequality theorem, we have:

[tex]\[ a + b > c \][/tex]

Substitute the given values:

[tex]\[ 13 + x > 21 \][/tex]

Now, solve for[tex]\( x \)[/tex]

[tex]\[ x > 8 \][/tex]

Similarly, for the other pair of sides:

[tex]\[ 21 + x > 13 \][/tex]

Solving for \( x \):

[tex]\[ x > -8 \][/tex]

However, since side lengths cannot be negative, we disregard the second inequality. Therefore, the compound inequality representing the range of possible values for [tex]\( x \) is \( 8 < x < 34 \).[/tex] This means that any value of [tex]\( x \)[/tex] between 8 and 34 (exclusive) will satisfy the conditions for the given triangle.

Answer: A, inside the circle.

Step-by-step explanation: Because the radius is wider than 4, (4,-1) would be just inside the circle instead of outside. Using the radius, you could determine that all points on the circle extend 5 units from its center, which means that the overall circumference would be past (4,-1).

Hope this helps,

LaciaMelodii :)

The answer is:

B. [tex]d\leq 1,640ft[/tex]

From the statement we know that the cheetah can reach a speed of 70 mph, but it can be maintained for no more than 1,640 feet.

The expression "no more than" means that at least it can be reached but never exceeded, it involves that the distance can be less or equal than 1,640 feet but never more than that.

So, the correct option is:

B. [tex]d\leq 1,640ft[/tex]

Have a nice day!

The answer is:

Benji requires 90mL per injection.

From the statement we know that dog's weight is 12 kg, and daily injections are required for 3 days, the dose rate is 7.5 mg/kg, so we need to calculate how many mL per injection does Benji require.

We have that:

[tex]Weight=12Kg\\\\Dose=7.5\frac{mL}{Kg}[/tex]

If the dose rate is 7.5 mL per each Kg, how many mL are required for 12 Kg? We can set it up using the following relation:

[tex]7.5mL=1Kg\\x=12Kg\\\\x=\frac{7.5mL*12Kg}{1Kg}=\frac{90mL.Kg}{1Kg}=90mL[/tex]

Hence, we have that there are needed 90 mL per injection.

Have a nice day!

Answer:

  (9x -2)(9x +2)

Step-by-step explanation:

Each of the terms in the difference is a perfect square, so the "perfect square trick" applies. The factors are the sum and difference of the square roots of the given terms.

  81x² - 4 = (9x +2)(9x -2)

Hi the answer is 344

Answer:

140

Step-by-step explanation:

54-75=-21

-21+81=60

60-(-27)=87 or 60+27=87

87+53=140

Answer:

The domain would be the set of all whole numbers.

Step-by-step explanation:

Integers are { ......-3, -2, -1, 0, 1, 2, 3....}

Whole numbers are {0, 1, 2, 3, ...... }

Real numbers are all numbers except imaginary number,

Positive integers are {1, 2, 3, 4, ....}

Given,

In the function f(x),

x represents the number of people in line,

We know that number of people can not be negative and it can be 0,

Thus, the possible value of x are 0, 1, 2, 3,......

Also, the domain of a function is the set of all possible value of input,

Since,  x represent the input for the function f(x),

Thus, the domain of f(x) would be the set of all whole number.

Second option is correct.

Answer:

That is true

Step-by-step explanation:

The ratio is a one-to-one measure, literally a ratio of the sides in reduced form.  The area is that one-to-one ratio squared.

Our numbers are already squared, so in order to find the one-to-one we have to take the square roots of both of them.  

[tex]\frac{\sqrt{4} }{\sqrt{64} } =\frac{2}{8} =\frac{1}{4}[/tex].

Answer:

True

step-by-step explanation:

Just in case you needed a second opinion.

Answer: Yes you can using the sum of internal angles in a triangle they add up to 180, so if you add the two given angle measures and them substract the result from 180 you will have the measure of the third angle. Hope this helps. :)

Step-by-step explanation:

According to the recursive formula,

[tex]a_2=a_1+4[/tex]

[tex]a_3=a_2+4=(a_1+4)+4=a_1+2\cdot4[/tex]

[tex]a_4=a_3+4=a_2+2\cdot4=a_1+3\cdot4[/tex]

and so on, with the general formula

[tex]a_n=a_1+(n-1)\cdot4[/tex]

Then

[tex]a_n=-2+4(n-1)=4n-6[/tex]

and the answer is C.

Answer:

C. an = 4n -6

Step-by-step explanation:

Only one of the offered choices gives a1=-2 for n=1.

___

The recursive formula tells you ...

a2 -a1 = 4

The only choices that increase by 4 when n increases by 1 are choices C and D. Of these, choice D gives a1=4·1+6 = 10 ≠ -2.

Choice C gives a1 = 4·1 -6 = -2, as required.

Answer:

  17.8 hours

Step-by-step explanation:

Serena's bonus on $1200 sales is 15%×$1200 = $180. In order to make $500 for the week, then she must have at least ...

  $500 - 180 = $320

in hourly pay.

At $18 per hour, that requires she work $320/($18/h) = 17.77_7 h.

Serena must work a minimum of about 17.8 hours to make $500.

_____

Comment on the answer

The exact result of the computation is 17 7/9 hours. Many payroll departments record hours to the nearest 1/4 or 1/10 hour. For Serena's pay to be at least $500, she must work 17.8 (rounded to tenths) or 18.0 (rounded to quarters) hours.

Answer:

y = 20

Step-by-step explanation:

x+y+z = 50

x/y = 1/4 so y = 4x

Substitute y = 4x into  x+y+z = 50

x + 4x + z = 50

5x + z = 50

y/z = 4/5 --> 4z = 5y so z =5/4 y

Substitute z =5/4 y into 5x + z = 50

5x + 5/4 y = 50

You can solve for x from these 2 equations

5x + 5/4 y = 50

y = 4x

Substitute y = 4x into 5x + 5/4 y = 50

5x + 5/4 (4x) = 50

5x + 5x = 50

10x = 50

  x = 5

y = 4x = 4 (5) = 20

Answer

y = 20

The sum of the numbers x, y, and z is 50. The ratio of x to y is 1:4, and the ratio of y and z is 4:5

The value of y =20

Given :

The sum of the numbers x, y, and z is 50

The ratio of x to y is 1:4, and the ratio of y and z is 4:5.

The sum of the numbers x, y, and z is 50

The equation becomes [tex]x+y+z=50[/tex]

The ratio of x to y is 1:4

[tex]\frac{x}{y} =\frac{1}{4} \\4x=y\\y=4x[/tex]

Now use the second ratio . the ratio of y and z is 4:5

[tex]\frac{y}{z} =\frac{4}{5}\\5y=4z\\Replace \; y=4x\\5(4x)=4z\\20x=4z\\z=5x[/tex]

Replace y=4x  and z=5x in the first equation

[tex]x+y+z=50\\x+4x+5x=50\\10x=50\\x=5[/tex]

Now we replace x with 5  and find out y

[tex]y=4x\\y=4(5)\\\y=20[/tex]

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Answer:

12 5/8 tons were delivered by the third truck

Step-by-step explanation:

25 = 6 4/8 + 5 7/8 + x

25 = 12 3/8 + x

- 12 3/8

12 5/8 = x

Answer:

6 3/4

Step-by-step explanation:

5 7/8 * 2 +6 1/2 + X = 25

Do the algebra.

x = 6 3/4