47. A movie based on a best-selling novel was recently released. Six hundred viewers of the
movie, 235 of whom had previously read the novel, were asked to rate the quality of the
movie. The survey showed that 141 of the novel readers gave the movie a rating of
excellent, while 248 of the non-readers gave the movie an excellent rating.
a. Develop an interval estimate of the difference between the proportions of the two
populations, using a .05 level of significance, as the basis for your decision.
b. Can we conclude, on the basis of a hypothesis test about p1 – p2, that the
proportion of the non-readers of the novel who thought the movie was excellent
is greater than the proportion of readers of the novel who thought the movie was
excellent? Use a .05 level of significance. (Hint: this is a one-tailed test.)
48. Employee panel preferences for three proposed company logo designs follow.
Number of Employees Preferring Design
= .05 and test to determine any difference in preference among the three logo
49. City planners are evaluating three proposed alternatives for relieving the growing traffic
congestion on a north-south highway in a booming city. The proposed alternatives are:
(1) designate high-occupancy vehicle (HOV) lanes on the existing highway, (2) construct
a new, parallel highway, and (3) construct a light (passenger) rail system.
In an analysis of the three proposals, a citizen group has raised the question of whether
preferences for the three alternatives differ among residents near the highway and non-
residents. A test of independence will address this question, with the hypotheses being:
H0: Proposal preference is independent of the residency status of the individual
Ha: Proposal preference is not independent of the residency status of the individual
A simple random sample of 500 individuals has been selected. The crosstabulation of the
residency statuses and proposal preferences of the individuals sampled is shown below.
Conduct a test of independence using
= .05 to address the question of whether
residency status is independent of the proposal preference.