A firm that produces light bulbs claims that their lightbulbs last 1500 hours, on average. You wonder if the average might differ from the 1500 hours that the firm claims. To explore this possibility you take a random sample of n = 25 light bulbs purchased from this firm and record the lifetime (in hours) of each bulb. You then conduct an appopriate test of hypothesis. Some of the information related to the hypothesis test is presented below.
Test of H0: = 1500 versus H1: 1500
Sample mean 1509.5
Sample standard deviation 24.27
Assuming the life length of this type of lightbulb is normally distributed, if you wish to conduct this test using a .05 level of significance, what are the critical values that you should use?