A Ackerman and Goldsmith (2011) found that students who studied text from

printed hardcopy had better test 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

= 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 ebooks

were significantly different from scores for the regular class? Use

a two-tailed test with = .05.

b) Construct the 90% confidence interval to estimate the mean exam score

if the entire population used e-books.

c) Write a sentence demonstrating how the results from the hypothesis test

and the confidence interval would appear in a research report.