A pizza delivery chain advertises that it will deliver your pizza in 40 minutes from when the order is placed. Being a skeptic, you decide to test and see if the mean delivery time is actually more than 40 minutes. For the simple random sample of 8 customers who record the amount of time it takes for each of their pizzas to be delivered, the mean is 47.6 minutes with a standard deviation of 11.5 minutes. Assume that the population distribution is approximately normal. Perform a hypothesis test using a 0.005 level of significance. Step 2 of 3: Compute the value of the test statistic. Round your answer to three decimal places.