1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
GarryVolchara [31]
3 years ago
6

Each year, all final year students take a mathematics exam. It is hypothesised that the population mean score for this test is 8

0. It is known that the population standard deviation of test scores is 13. A random sample of 23 students take the exam. The mean score for this group is 71. a)Calculate the 90% confidence interval for the population mean test score. Give your answers to 2 decimal places.
Mathematics
1 answer:
VMariaS [17]3 years ago
7 0

Answer:

The 90% confidence interval for the population mean test score is between 66.54 and 75.46.

Step-by-step explanation:

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

\alpha = \frac{1 - 0.9}{2} = 0.05

Now, we have to find z in the Ztable as such z has a pvalue of 1 - \alpha.

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

Now, find the margin of error M as such

M = z\frac{\sigma}{\sqrt{n}}

In which \sigma is the standard deviation of the population and n is the size of the sample.

M = 1.645\frac{13}{\sqrt{23}} = 4.46

The lower end of the interval is the sample mean subtracted by M. So it is 71 - 4.46 = 66.54

The upper end of the interval is the sample mean added to M. So it is 71 + 4.46 = 75.46

The 90% confidence interval for the population mean test score is between 66.54 and 75.46.

You might be interested in
Help me pls, I tried to do it and got the incorrect Anwser
dedylja [7]
It would be option 4) 2 because the line is perpendicular hope this helps!!
6 0
2 years ago
Read 2 more answers
What is 1/3 of 120???
Vinil7 [7]
The answer for (1/3)*120 is 40
6 0
3 years ago
Read 2 more answers
The volume of this right prism is 2,500 ft³. What is the height, x, of the prism? x = ft
Natalka [10]

The height x of the right prism is 10 ft if the volume of this right prism is 2,500 ft³.

<h3>What is a rectangular prism?</h3>

It is defined as the six-faced shape, a type of hexahedron in geometry.

It is a three-dimensional shape. It is also called a cuboid.

From the figure:

Volume = 2500 cubic ft

(10)(x)(25) = 2500

250x = 2500

x = 10 ft

Thus, the height x of the right prism is 10 ft if the volume of this right prism is 2,500 ft³.

Learn more about the rectangular prism here:

brainly.com/question/21308574

#SPJ1

6 0
2 years ago
Which equations represent the line that is parallel to 3x – 4y = 7 and passes through the point (-4,-2)? Select two
seropon [69]

Answer:

4y = 3x + 4

3x-4y = -4 is correct

Step-by-step explanation:

This is what we do.

We first express the first equation in the form;

y = mx + c

where m represents the slope of the line

Thus we have;

4y = 3x -7

divide through by 4

y = 3/4x -7/4

Thus the slope here is the coefficient of x which is 3/4

Now, since the lines are parallel, it means that their slopes are equal

So the slope of the other line too is 3/4

We now use the point slope form to find the equation of this other line

Mathematically, that would be;

y-y1 = m(x-x1)

where (x1,y1) = (-4,-2)

Substituting this into the point slope equation, we have;

y-(-2) = 3/4(x-(-4))

y + 2 = 3/4(x + 4)

Cross multiply

4y + 8 = 3x + 12

4y = 3x + 12-8

4y = 3x + 4

5 0
3 years ago
A bee flies 25 m north of the hive then 10 m east 5 m west and 10 m south. How far north and east of the hive is it now? Explain
mafiozo [28]

Answer:

20 meters north.

Step-by-step explanation:

(I did it on a paper not to lose track.) First we go 25 north. Then ten east. Five south. And 10 west again. So in East/West we didn't move but we moved 5 down/south so we are still at twenty. If you don't understand still draw it on a paper.

5 0
3 years ago
Other questions:
  • Solve the following inequality. Then place the correct answer in the box provided. Answer in terms of a mixed number. 12z - 3 ≥
    12·1 answer
  • The vector has components +5 and +7 along the x- and y-axes respectively. along a set of axes rotated 90 degrees counterclockwis
    14·2 answers
  • Zach has a credit card with a $500 limit. He has used the card to pay $120.32 for groceries. How much more can Zach spend withou
    12·1 answer
  • Brandon has a 55-gallon fish tank. He estimates he can drain the tank at an average rate of 11 gallons per minute. In a linear m
    5·1 answer
  • My answer is incorrect.. I need help and explanation.. Thank you
    11·1 answer
  • Explain how to make these couculations mentaly a. 99+54 b.244-99
    13·1 answer
  • Colin invests £5000 into his bank account.
    9·1 answer
  • Graph the line with this equation
    15·2 answers
  • Help me plz and thank you
    7·1 answer
  • Jinny is selling bracelets for $2.00. So far, she has earned $180.00. She needs to earn more than $228.00 in order to meet her g
    14·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!