# Question

A bank manager wants to know the mean amount of mortgage paid per month by homeowners in an area. A random sample of 120 homeowners selected from this area showed that they pay an average of $1575 per month for their mortgages. The population standard deviation of such mortgages is $215.

a. Find a 97% confidence interval for the mean amount of mortgage paid per month by all homeowners in this area.

b. Suppose the confidence interval obtained in part a is too wide. How can the width of this interval be reduced? Discuss all possible alternatives. Which alternative is the best?

a. Find a 97% confidence interval for the mean amount of mortgage paid per month by all homeowners in this area.

b. Suppose the confidence interval obtained in part a is too wide. How can the width of this interval be reduced? Discuss all possible alternatives. Which alternative is the best?

## Answer to relevant Questions

A marketing researcher wants to find a 95% confidence interval for the mean amount that visitors to a theme park spend per person per day. She knows that the standard deviation of the amounts spent per person per day by all ...You are interested in estimating the mean age of cars owned by all people in the United States. Briefly explain the procedure you will follow to conduct this study. Collect the required data on a sample of 30 or more cars ...a. Find the value of t for the t distribution with a sample size of 21 and area in the left tail equal to .10. b. Find the value of t for the t distribution with a sample size of 14 and area in the right tail equal to ...Suppose, for a sample selected from a population, = 25.5 and s = 4.9. a. Construct a 95% confidence interval for µ assuming n = 47. b. Construct a 99% confidence interval for µ assuming n = 47. Is the width of the 99% ...Jack’s Auto Insurance Company customers sometimes have to wait a long time to speak to a customer service representative when they call regarding disputed claims. A random sample of 25 such calls yielded a mean waiting ...Post your question

0