Auto Loans ~ George works for a credit union that serves a large, urban area. For his
Question:
Auto Loans ~ George works for a credit union that serves a large, urban area. For his annual report, he wants to estimate the mean interest rate for 60-month fixed-rate auto loans at lending institutions (banks, credit unions, auto dealers, etc.) in his area. George selects a random sample of 12 lending institutions and obtains the following rates:
6.05 | 6.45 | 4.01 | 7.8 | 6.5 | 7.82 |
6.5 | 8.74 | 6.35 | 7.4 | 7.2 | 5.55 |
Round all calculated answers to 4 decimal places.George calculates a sample mean of 6.6975 and a sample standard deviation of 1.2289.
1. Calculate a 99% confidence interval for the mean interest rate for 60-month fixed-rate auto loans at lending institutions in George’s area. Assume necessary conditions have been met and round your result to 4 decimal places.
George calculates a sample mean of 6.6975 and a sample standard deviation of 1.2289.1. Calculate a 99% confidence interval for the mean interest rate for 60-month fixed-rate auto loans at lending institutions in George’s area. Assume necessary conditions have been met and round your result to 4 decimal places.
( , )
After calculating the interval, George decides he wants to estimate the interest rate for 60-month fixed-rate auto loans at 99% confidence with a margin of error of no more than 0.23.2. Using George’s initial sample results as a starting point, how large a sample would George need to collect to accomplish his goal? Use a t∗ value rounded to 3 decimal places in your calculations and give your answer as an integer.
n=