It is desired to estimate the average time it takes Statistics students to finish a computer project to within two hours at 90% reliability. It is estimated that the standard deviation of the times is 14 hours. How large a sample should be taken to get the desired interval? n = 231 n = 189 n = 325 n = 133

Answers

Answer 1

Answer:

n = 133.

Step-by-step explanation:

We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:

[tex]\alpha = \frac{1 - 0.9}{2} = 0.05[/tex]

Now, we have to find z in the Z-table as such z has a p-value of [tex]1 - \alpha[/tex].

That is z with a pvalue of [tex]1 - 0.05 = 0.95[/tex], so Z = 1.645.

Now, find the margin of error M as such

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.

Standard deviation of the times is 14 hours.

This means that [tex]\sigma = 14[/tex]

How large a sample should be taken to get the desired interval?

Within 2 hours, which means that we want n for which M = 2. So

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

[tex]2 = 1.645\frac{14}{\sqrt{n}}[/tex]

[tex]2\sqrt{n} = 1.645*14[/tex]

Dividing both sides by 2

[tex]\sqrt{n} = 1.645*7[/tex]

[tex](\sqrt{n})^2 = (1.645*7)^2[/tex]

[tex]n = 132.6[/tex]

Rounding up, n = 133.


Related Questions

If anyone could help it would be great

Answers

Answer:

See the picture

Step-by-step explanation:

Solved, green filled arrows in the picture

In ΔDEF, the measure of ∠F=90°, DF = 3, ED = 5, and FE = 4. What is the value of the tangent of ∠E to the nearest hundredth?

Answers

Answer:0.75

Step-by-step explanation:

trust me

Help plz:)))I’ll mark u Brainliest

Answers

Answer:

[tex]sin^{-1}(\frac{51}{53})\\=74.21\\[/tex]

≈74

y is directly proportional ( x+2)²
when x = 8 y= 250
find y when x = 4​

Answers

Answer:

y=90 when x=4

Step-by-step explanation:

We are given that

[tex]y\propto (x+2)^2[/tex]

When x=8 and y=250

We have to find the value of y when x=4

[tex]y=k(x+2)^2[/tex]

Where k= Proportionality constant

Substitute the values

[tex]250=k(8+2)^2[/tex]

[tex]250=100k[/tex]

[tex]k=\frac{250}{100}[/tex]

[tex]k=5/2[/tex]

Now, substitute x=4 and k=5/2

Then, we get

[tex]y=\frac{5}{2}(4+2)^2[/tex]

[tex]y=\frac{5}{2}\times 36[/tex]

[tex]y=90[/tex]

Which factorization is equivalent to this expression?
−20x − 5y

Answers

Answer:

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

-5(4x+y) is the answer ahfjdndickdndndjdjsnsndndnd

what is the time in Nigeria WHOEVER GETS IT ROGHT I WILL GIVE YOU BRAINLIEST​

Answers

It is currently 7:55pm in Nigeria

Answer:

7:55 PM

hope this helps

have a good day :)

Step-by-step explanation:

I can Multiply a 4x4 matrix by a 4x3 matrix. The resulting matrix will be a?

Answers

Answer:

21

Step-by-step explanation:

how to find the vat on 14% of 1800​

Answers

Answer:

14/100*1800

25200/100

252

Step-by-step explanation:

therefore vat=252

There was 1\3of a box of cereal left. Four brothers shared it evenly. How much of the original box of cereal did each brother get?​

Answers

9514 1404 393

Answer:

  1/12 box

Step-by-step explanation:

Each brother gets 1/4 of the remaining 1/3 box, so ...

  (1/4)(1/3 box) = 1/(4·3) box = 1/12 box

Each brother gets 1/12 of the original box.

PLS help



Which of the following statements are true about the solids shown above

Answers

Answer:

kkkkkk

Step-by-step explanation:

In a math class with 20 students, a test was given the same day that an assignment was due. There were 11 students who passed the test and 15 students who completed the assignment. There were 9 students who passed the test and also completed the assignment. What is the probability that a student chosen randomly from the class failed the test and did not complete the homework?

Answers

Answer: 3/20 or .15

Step-by-step explanation:

A desktop is shaped like a semicircle with a diameter of 28 what is the area of the desktop?

Answers

Answer:

307.72

Step-by-step explanation:

if the diameter is 28 then the radius is 14 (half of the diameter)

Simplify 6(2x-y) - 3(5x+2y)

-3x - 12y

O 3x + 12y

9x + 14y

Which one is the answer

Answers

It’s going to be -3x-12y

please answer this, I need help ​

Answers

Answer:

-$7

Step-by-step explanation:

20 - 15 = 5

5 + 5 = 10

10 - 10 = 0

0 - 7 = -7

Hey! Can someone please help me with this question? Really appreciate it

Answers

Answer:

[tex]d = 0.112* 10^3[/tex]

Step-by-step explanation:

Given

[tex]h = 8.4 * 10^3[/tex]

[tex]d = \sqrt{\frac{3h}{2}}[/tex]

Required

Find d

We have:

[tex]d = \sqrt{\frac{3h}{2}}[/tex]

Substitute: [tex]h = 8.4 * 10^3[/tex]

[tex]d = \sqrt{\frac{3*8.4 * 10^3}{2}}[/tex]

[tex]d = \sqrt{\frac{25.2 * 10^3}{2}}[/tex]

[tex]d = \sqrt{12.6 * 10^3}[/tex]

Express as:

[tex]d = \sqrt{1.26 *10* 10^3}[/tex]

[tex]d = \sqrt{1.26 *10^4}[/tex]

Split

[tex]d = \sqrt{1.26} *\sqrt{10^4}[/tex]

[tex]d = 1.122* 10^2[/tex]

To write in form of: [tex]a * 10^b[/tex]

The value of a must be: [tex]0 \le a \le 1[/tex]

So, we have:

[tex]d = 0.1122* 10 * 10^2[/tex]

[tex]d = 0.1122* 10^3[/tex]

Approximate

[tex]d = 0.112* 10^3[/tex]

plz plz plz plz help me​

Answers

Answer:

Solution given:

perpendicular [P]=15m

base[B]=8m

hypotenuse [H]=17m

rate :4 plants per square metre

no of plants=?

we have

Area of triangular garden: ½(P*B)=½(15*8)=60m²

Now

Total no of plants =rate ×Area =4×60=240

Michael needs 240 plants in the garden

Answer for brainlest

Answers

Answer:

Alternate interior angles.

Step-by-step explanation:

A teacher is interested in performing a hypothesis test to compare the mean math score of the girls and the mean math score of the boys. She randomly selects 10 girls from the class and then randomly selects 10 boys. She arranges the girls' names alphabetically and uses this list to assign each girl a number between 1 and 10. She does the same thing for the boys. She pairs each girl with the boy having the same number. She then performs a paired Do you think that in this situation a paired is the most appropriate procedure?

Answers

Answer:

No

Step-by-step explanation:

A matched pair design is used when we have two different observation about a certain experiment for each subject such that there is a natural pairing between the two population.

In the scenario described above, we have 20 subjects of which 10 are boys and 10 are girls.

Matching boys and girls having similar numbers does not depict natural pairing and thus using a matched paired test would be inappropriate. The test to use for such experiment is the two population t test.

Help I need this answer ASAP

Answers

Answer: c

Step-by-step explanation: because yes

Answer:

d po answer

yan po sinagot ko

hehe

Tom is throwing darts at a target. In his last 30 throws, Tom has hit the target 20 times. You want to know the estimated probability that exactly one out of the next three throws does not hit the target.

Categorize the simulations as correct or incorrect simulations of Tom’s scenario.

Roll a six-sided die three times. The
numbers 1 to 4 represent hits, and
5 and 6 represent misses.
Spin a spinner with three equal sections
three times. On the spinner, one section
represents a miss and two sections
represent hits.
Generate a set of three numbers using
a number generator with numbers
between 0 and 9. The numbers 0 to 7
represent hits, and 8 and 9 represent
misses.
Generate a set of three numbers using
a number generator with numbers
between 0 and 8. The numbers 0 to 5
represent hits, and 6 to 8 represent
misses.
Spin a spinner with six equal sections
three times. On the spinner, four
sections represent hits and two
sections represent misses.

Answers

Answer:

no

Step-by-step explanation:

Let f (x) = 10/x-4
What is the average rate of change of f (x) from 2 to 8 ?

Enter your response as a decimal.

Answers

Answer:

1.875

Step-by-step explanation:

The rate of change is the derivative of the function.

[tex]f(x) = \frac{10}{x-4}\\\\f'(x)=10\times \frac {d}{dx}\frac{1}{x-4}\\\\f'(x)=\frac{-10}{(x-4)^{2}}\\\\f'(2) = \frac{-10}{(2-4)^{2}} =-2.5\\\\f'(8)= \frac{-10}{(8-4)^{2}} =-0.625\\[/tex]

So, the rate of change is

f'(8) -  f'(2) = - 0.625 + 2.5 = 1.875

If you rolled two dice, what is the probability
that you would roll a sum of 4?
Give your answer as a simplified fraction. Enter
the number that belongs in the green box.
3
second
first
1 2
4 5 6
11,1 1,2 1,3 1,4 1,5 1,6
22,1 2,2 2,3 2,4 2,5 2,6
33,1 3,2 3,3 3,4 3,5 3,6
4 4,1 4,2 4,3 4,4 4,5 4,6
55,1 5,2 5,3 5,4 5,5 5,6
6 6,1 6,2 6,3 6,4 6,5 6,6
Enter

Answers

Answer:

1/12

Step-by-step explanation:

3/36=1/12

The diameter of a cone-shaped storage tank is 14 feet and it's height is 9 feet. Find the volume of liquid the tank can hold. Round your answer to the integer, if necessary. Use the approximate of value of /pi , that is 3.14.

Answers

Answer:

461.6 ft³

Step-by-step explanation:

V(cone) = 1/3πr²h

= 1/3π(7²)(9)

= 49·3π

= 147(3.14)

= 461.6 ft³

louis makes a$15 [er hour working at the mall. which equation represents the total amout of money, d, louis makes in h hours?

Answers

Answer:

15H = D

Step-by-step explanation:

Given that Louis makes $ 15 per hour working at the mall, to determine which equation represents the total amout of money, D, Louis makes in H hours, the following calculation must be performed:

15H = D

So, for example, if Louis worked 10 hours, the equation would operate as follows:

15 x 10 = D

150 = D

Kristy had a piece of fabric that she cut into 8 equal squares. Each square has area 0.625 ft2. What is the area of Kristy's original piece of fabric?

ft2


PLS HELPPP

Answers

Answer:

5[tex]ft^2[/tex] is the area of the original piece of fabric.

Step-by-step explanation:

0.625 x 8 = 5

In the figure CE=34 cm and DE=30 cm. What is the radius of the circle?

Answers

The radius divides the diameter into 2, and the radius of the circle is 16 units

How to determine the radius?

The radius of the circle and the tangent line meet at a right angle.

This means that:

CE² = r² + DE² ------ Pythagoras theorem

So, we have:

34² = r² + 30²

Evaluate the squares

1156 = r² + 900

Rewrite as:

r² = 1156 - 900

Evaluate

r² = 256

Take the square root of both sides

r = 16

Hence, the radius of the circle is 16 units

Read more about radius at:

https://brainly.com/question/9554871

#SPJ2

A line passes through the point (2, 10) and has a y-intercept of 4. What is the equation of the line? Help me please

Answers

Step-by-step explanation:

If it's a straight line the use formula

[tex]y = mx + c[/tex]

m= gradient of line

c = y-intercept

we know that y-intercept is 4 so coordinate is

(0,4)

Equation also passes (2,10)

Use both coordinate to find gradient

m= vertical distance / horizontal distance

= (10-4) / (2-0)

= 3

y = 3x + 4

pls help!! Need the answer asap!!

Answers

Step-by-step explanation:

19+k=90°

k=90-17

k=71°

stay safe healthy and happy .
As you can see, that Angle AOC is 90°,19°+k = 90°k = 90°-19°k = 71°,Option (B) is correct. HOPE IT HELPS YOU!!!

find the length of the missing side
help!

Answers

Answer:

B would be 72 using a^2+b^2=c^2

Step-by-step explanation:

30^2 + x =78^2

in other words

900 + x =6084

6084-900= 5184

The square root of 5184 is 72

According to the following graph, which service took the longest to download the podcast? How much longer did it take than Groove Box in minutes and seconds?

51000711

The service will take the longest to download the podcast.

It will take minutes and seconds longer than Groove Box.

Answers

Answer:

- Top Hat

- 14

- 37

Step-by-step explanation:

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