A manufacturer of cell phone batteries claims that the median life of a battery is more than 40 hours. Suppose a random sample of 75 batteries finds that 32 have a life of more than 40 hours. Using α = .05, can we conclude that the battery life is more than 40 hours?
A) Reject the null hypothesis; z = 1.38.
B) Do not reject the null hypothesis; z = 1.38.
C) Reject the null hypothesis; z = −1.38.
D) Do not reject the null hypothesis; z = −1.38.

Question

Quizplus · Accepted Answer

Reject H₀ if Z > 1.645 Z == −1.38 The test failed to reject H₀, so we can't conclude that the battery life is more than 40 hours.

A Manufacturer of Cell Phone Batteries Claims That the Median