Suppose the math department chair at a large state university wants to estimate the average overall rating, out of five points, that students taking Introductory Statistics gave their lecturers on their end-of-term evaluations. She selects a random sample of 40 evaluations and records the summary statistics shown.

The department chair determines the standard error using?, the standard deviation calculated from all student evaluations submitted to her department. Assume the Statistics lecturers' ratings have the same standard deviation. Use this information to find the margin of error and the lower and upper bounds of a 95% confidence interval form the mean overall rating students gave their Introductory Statistics lecturers. Round your answers to the nearest hundredth.

Margin of error =

Scroll Lower bound =

Upper bound =

Sample Sample size mean x 3.8303 n 40 Sample standard deviation S 1.0112 Population standard deviation 6 1.0750 Standard Confidence error level C 95% 07 0.1700