In the year 2001, the average GPA of the college graduates was 3.1. a recent survey of 1000 students estimated an average GPA of 3.3 with the standard deviation of 3.
a) do a two tailed test at alpha = .05 to findout if there is grade inflation since 2001.
b) make a 95% confidence interval
c) if the desired error of the estimation is less than 0.14 with 98% confidence, what must the sample size be?