Nationwide, the average time until a electric utility customer service representative answers a call is 260 second. The Gigantic Kilowatt Energy Company randomly sampled 30 calls and found that, on average, they were answered in 227 second with a population standard deviation of 40 seconds. Can the company claim that they are faster than the average utility at a = 0.05?
yes, because the test value -4.52 falls int he critical region
no, because the test value -0.83 falls in the critical region.
yes, because the test value -0.15 falls in the critical region.
no, because the test value -0.15 falls in the critical region.