It is suspected that the incidence of downloading music from

It is suspected that the incidence of downloading music from the Internet decreased between the years 2003 and 2005, due to the recording industry filing lawsuits. A 95% confidence interval, using simple random sampling techniques, for the true difference p₁ - p₂ in the proportion of Internet users who download music onto their computers is (0.0381, 0.1019). Where p₁ is the true proportion of Internet users who downloaded music in 2003.

Assume the number of success and failures are each 10 or more in both samples.

A.

This confidence interval is evidence that the lawsuits did not change the music downloading habits of Internet users.

B.

This confidence interval is evidence that the lawsuits did help decrease the incidence of music downloading by Internet users.

C.

This confidence interval is evidence that the lawsuits did not help decrease the incidence of music downloading by Internet users.

D.

It is not possible to determine any evidence about the lawsuits from this confidence interval.

Solution

B.

This confidence interval is evidence that the lawsuits did help decrease the incidence of music downloading by Internet users.