Let’s imagine that you are the head of quality control for a company that makes light bulbs. You want to test at a 5% significance level, a report that the company’s light bulbs last more than 1000 hours. You randomly select and test 50 bulbs and find the mean life of the bulbs is 925 hours with a standard deviation 67 hours. H0: mean µ = 1000 hours. Note the null hypothesis will always contain the equality sign.
H1: mean µ > 1000 hours. This is the company’s claim. This is also a 1-tailed test.
Please calculate the test statistic, as well as the p-value. Please also interpret the test results.