Question

A confidence interval, at the 95% confidence level will be used to answer what the mean...

A confidence interval, at the 95% confidence level will be used to answer what the mean annual salary of a Ford car owner is. Data was collected from 34 Ford car owners across the country. the mean annual salary of the 34 Ford owners was 225000. The standard deviation of all Ford owners is known to be $970.

a. The value at the center of the confidence interval represents what? (sample mean, standard dev., population mean, or sample size)

b. is z or t used when building the confidence interval?

c. determine the value of the letter indicated in part b?

d. What is the lower and upper bounds of the confidence interval?

d. if the sample size is decreased by 19 Ford owners, what would happen to the confidence interval? (narrows, widens, or stays the same).

Math   Statistics-And-Probability   
0 0
Add a commentTranscribed image text
Next >

Homework Answers

Answer #1

a) Population mean.

b) z is used when building the confidence interval.

c) At 95% confidence level, the critical value is z0.025 = 1.96

d) The 95% confidence interval is

Lower bound = 224673.947

Upper bound = 225326.053

e) The confidence interval would narrows.

As the sample size decreases, the margin of error also decreases. So that the width of the confidence interval becomes narrower.

0 0
Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Log In

Sign Up

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
Use the standard normal distribution or the​ t-distribution to construct a 95% confidence interval for the...
Use the standard normal distribution or the​ t-distribution to construct a 95% confidence interval for the population mean. Justify your decision. If neither distribution can be​ used, explain why. Interpret the results. In a random sample of fortyone ​people, the mean body mass index​ (BMI) was 27.7 and the standard deviation was 6.24 Which distribution should be used to construct the confidence​ interval? Choose the correct answer below. (Use a t-distribution because the sample is random n>=30, and o is...
Suppose a 95% confidence interval for the mean salary of college graduates in a town in...
Suppose a 95% confidence interval for the mean salary of college graduates in a town in Mississippi is given by [$36,815, $43,185]. The population standard deviation used for the analysis is known to be $13,000. [You may find it useful to reference the z table.] a. What is the point estimate of the mean salary for all college graduates in this town? b. Determine the sample size used for the analysis. (Round "z" value to 3 decimal places and final...
Construct a 95% confidence interval for the population mean. A sample of 34 college students had...
Construct a 95% confidence interval for the population mean. A sample of 34 college students had mean annual earnings of $4520 with a standard deviation of $677
Find the margin of error for a​ 95% confidence interval for estimating the population mean when...
Find the margin of error for a​ 95% confidence interval for estimating the population mean when the sample standard deviation equals 90 with a sample size of​ (i) 484 and​ (ii) 1600 ​(i) Find the margin of error for a​ 95% confidence interval for estimating the population mean when the sample standard deviation equals 90 with a sample size of 484 (ii). ​(ii) Find the margin of error for a​ 95% confidence interval for estimating the population mean when the...
What is the lower bound of a 95% confidence interval with a sample mean of 22,...
What is the lower bound of a 95% confidence interval with a sample mean of 22, population standard deviation of 10, and sample size of 40. Question 1 options: A. 12 B.18.90 C. 25.10 D. 22
The width of a confidence interval estimate for a population mean when the population standard deviation...
The width of a confidence interval estimate for a population mean when the population standard deviation is known will (A)   become narrower if the size of the sample being used is increased and the confidence level is unchanged. (B)    not change if only the sample size is increased. (C)    become wider if the sample size remains the same and the confidence level decreases. (D)   become narrower if the size of the sample is decreased and the confidence level is unchanged....
Assume that a sample is used to estimate a population mean μμ. Find the 95% confidence...
Assume that a sample is used to estimate a population mean μμ. Find the 95% confidence interval for a sample of size 65 with a mean of 83.2 and a standard deviation of 7.7. Enter your answer as an open-interval (i.e., parentheses) accurate to 3 decimal places. 95% C.I. =
Find the margin of error for a​ 95% confidence interval for estimating the population mean when...
Find the margin of error for a​ 95% confidence interval for estimating the population mean when the sample standard deviation equals 100 with a sample size of​ (i)484 and​ (ii)1521. What is the effect of the sample​ size?
Assume that a sample is used to estimate a population mean μμ. Find the 95% confidence...
Assume that a sample is used to estimate a population mean μμ. Find the 95% confidence interval for a sample of size 901 with a mean of 34.3 and a standard deviation of 11.9. Enter your answer as a tri-linear inequality accurate to 3 decimal places. < μ <
Assume that you want to construct a​ 95% confidence interval estimate of a population mean. Find...
Assume that you want to construct a​ 95% confidence interval estimate of a population mean. Find an estimate of the sample size needed to obtain the specified margin of error for the​ 95% confidence interval. The sample standard deviation is given below. Margin of errors=​$6​, standard deviation=​$22 The required sample size is __
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT