Amanufacturerclaimsthatthemeanlifetimeofitsfluorescentbulbsis1000 hours. A homeowner selects 40 bulbs and finds the mean lifetime to be 990 hours with a population standard deviation of 80 hours. Test the manufacturer's claim. Use α = 0.05.
(a) State the Null and Alternative Hypothesis for this test.
(b) Draw the critical region sketch using the 5% level of significance.
(c) Calculate the test statistic.
(d) Make a decision concerning the null hypothesis.
(e) Write a conclusion concerning the claim.