Question

A study was conducted to determine if the salaries of librarians from two neighboring cities were equal. A sample of 15 librarians from each city was randomly selected. The mean from the first city was​ $28,900 with a standard deviation of​ $2300. The mean from the second city was​ $30,300 with a standard deviation of​ $2100. Construct a​ 95% confidence interval for mu 1minusmu 2.

Answer 1

For the first city, the 95% confidence interval would be:

28,900 +/- 2300 x 3 = 28,900 +/-6900$

For the second city, the 95% confidence interval would be:

30,300 +/- 2100 x 3 = 30,300 +/- 6300$