A machine is adjusted such that the average weight of the detergent boxes is 300 grams. The weight distribution of the boxes is normal with s = 10 grams. Due to the numerous vibrations experienced by the machine, it is believed that the average filling weight could vary. Samples of 30 containers are taken at random regularly to verify the accuracy of the machine adjustment. The machine is adjusted if the average weight is less than 296.69 or more than 303.31 grams. Calculate the power of the test if in reality the true mean ( ) of the population is 293.