34. Here is a sample ofACT scores (average of the Math, English, Social Science, and Natural Science scores)

for students taking college freshman calculus:

24.00 28.00 27.75 27.00 24.25 23.50 26.25 24.00 25.00 30.00 23.25 26.25 21.50 26.00 28.00 24.50 22.50 28.25 21.25 19.75

a. Using an appropriate graph, see if it is plausible that the observations were selected from a normal distribution.

b. Calculate a two-sided 95% con dence interval for the population mean.

c. The university ACT average for entering freshmen that year was about 21. Are the calculus students better than average, as measured by the ACT?