Two Cal Poly freshmen gathered data on the prices for a random sample of 30 textbooks from the campus bookstore.They found the average price was $82.96, and the standard deviation of prices was $7.29.The data were not strongly skewed.

c. Identify (in words and using an appropriate symbol) the parameter of interest.

d. Use the 2SD approach to nd a 95% condence interval for the parameter.

e. Interpret the interval from part d. in context.