The below data contains the amount that a sample of 28 students spent for lunch ($) at a campus cafeteria:

23 27 26 25 40 19 26 36 23 33 23

11 38 21 26 23 21 33 40 15 55 30

41 31 47 37 33 28

Construct a 95% confidence interval estimate for the population mean amount spent for lunch at the campus cafeteria. Interpret the interval constructed at a)

1. What assumption do you need to make about the population to construct the interval at a)? Given the above data, do you thing the assumption needed in valid? Explain.
2. Describe the shape of the distribution of the above data. For this above data, construct and graph a frequency distribution with 4 intervals in the frequency.

Present results with 4 decimals.