You are interested in the question how long Dutch scuba-divers can stay underwater. You heard that the average number of minutes Dutch scuba-divers can dive without coming to the surface equals 68 minutes. You don't believe that's true and decide to conduct a test. Your null hypothesis is that the population mean equals 68. Your alternative hypothesis is that the population mean differs from 68. You question 40 randomly selected Dutch scuba-divers and discover that they can stay underwater for only 64 minutes. The standard deviation is 3 minutes. Do you reject your null hypothesis?