Ackerman and Goldsmith 2011 found that students who studied

Ackerman and Goldsmith (2011) found that students who studied text from printed hardcopy had better scores than students who studied from text presented on a screen. In a related study, a professor noticed that several students in a large class had purchased the e-book version of the course textbook. For the final exam, the overall average for the entire class was µ=81.7, but the n=9 students who used e-books had a mean of M=77.2 with a standard deviation of s=5.7.

a) Is the sample sufficient to conclude that scores for students using e-books were significantly different from scores for the regular class? Use a two-tailed test with =.01.

b) Construct the 95% confidence interval to estimate the mean exam score if the entire population used e-books.

Solution

a) Two tailed test