1. Replacement Costs: Transmissions You work for a consumer advocate agency and want to estimate the population mean cost of replacing a car’s transmission. As part of your study, you randomly select...

1. Replacement Costs: Transmissions You work for a consumer advocate agency and want to estimate the population mean cost of replacing a car’s transmission. As part of your study, you randomly select 50 replacement costs and find the mean to be $2650.00. Assume the population standard deviation is $425.00. Construct a 95% confidence interval for the population mean replacement cost. Interpret the results.

2. Repair Costs: Refrigerators In a random sample of 60 refrigerators, the mean repair cost was $150.00. Assume the population standard deviation is $15.50. Construct a 99% confidence interval for the population mean repair cost. Interpret the results.

3. Repeat Exercise 37, changing the sample size to n = 80. Which confidence interval is wider?

4. Repeat Exercise 38, changing the sample size to n = 40. Which confidence interval is wider?