What type of car is more popular among college students, American or foreign? One hundred fifty -nine college students were randomly sampled and each was asked which type of car he or she prefers.. A computer package was used to generate the printout below of a 90% confidence interval for the proportion of college students who prefer American automobiles. SAMPLE PROPORTION = .396 SAMPLE SIZE = 159 UPPER LIMIT = .472 LOWER LIMIT = .320 Which of the following is a correct practical interpretation of the interval?
A) We are 95% confident that the proportion of all college students who prefer American cars falls between .320 and .472.
B) We are 95% confident that the proportion of the 159 sampled students who prefer American cars falls between .320 and .472.
C) 95% of all college students prefer American cars between .320 and .472 of the time.
D) We are 95% confident that the proportion of all college students who prefer foreign cars falls between .320 and .472.

Question

Quizplus · Accepted Answer

The correct interpretation of a confidence interval is that we are 90% confident (not 95%) that the true proportion of all college students who prefer American cars falls between 0.320 and 0.472.

What Type of Car Is More Popular Among College Students