A telemarketing company located in Los Angeles has established a guideline stating that the average time for each completed call should be no more than 4 minutes. Recently the operations manager was concerned that calls were taking too long. The operations manager did not wish to assert that the calls were taking too long if the sample data did not strongly indicate this. A sample of 12 calls was selected and the following times (in seconds) were recorded.
194 278 302 140 245 234 268 208 302 190 320 255
Test at the 0.10 significance level using the p-value approach. (Assume that call times are normally distributed. Suppose you wished to conduct the test in part b using X as the test statistic.