In a recent year, 77.8% of recorded music sales were full-length CDs, 12.8% digital downloads, 3.8% singles, and the rest a mixture of other formats. A survey of college students and their recent music purchases indicated that out of 200 purchases, 48 were downloads, 135 were full-length CDs, 10 were singles, and the rest fit into the “other” category. At the 0.05 level of significance is there sufficient evidence to conclude that at least one of the proportions differs from its original value?
Perform these steps.
a. State the hypotheses and identify the claim.
b. Find the critical value.
c. Compute the test value.
d. Make the decision.
e. Summarize the results.
Use the traditional method of hypothesis testing unless otherwise specified.