Question

(CO 5) A light bulb manufacturer guarantees that the mean life of a certain type of light bulb is at least 720 hours. A random sample of 51 light bulbs as a mean of 712.8 hours with a population standard deviation of 62 hours. At an α=0.05, can you support the company’s claim using the test statistic?

Claim is the null, reject the null and cannot support claim as test statistic (-0.83) is in the rejection region defined by the critical value (-1.645)

Claim is the null, fail to reject the null and support claim as test statistic (-0.83) is not in the rejection region defined by the critical value (-1.645)

Claim is the alternative, reject the null and support claim as test statistic (-0.83) is not in the rejection region defined by the critical value (-1.96)

Claim is the alternative, fail to reject the null and cannot support claim as the test statistic (-0.83) is in the rejection region defined by the critical value (-1.96)

Answer 1