Wax-com Electronics Inc. claims that a certain circuit board has a median operating life of less than 20,000 hours. A random sample of 25 such circuit boards showed 8 circuit boards failing before 20,000 hours and 17 circuit boards failing after 20,000 hours. Assume the useful life of the circuit board is not normally distributed. At α = .05, can it be concluded that the sample contradicts the company's claim? Assume the useful life of the circuit board is not normally distributed.
A) Reject the null hypothesis.
B) Do not reject the null hypothesis.

Question

Quizplus · Accepted Answer

H₀: M_d ≥ 20,000; H_A: M_d < 20,000 Z === −1.6 Since −1.6 > −1.645, the test failed to reject H₀. It appears that the company's claim is not correct. The median operating life of the circuit board is not less than 20,000 hours.

Wax-Com Electronics Inc