Suppose that the lengths of lives of houseflies has been normally distributed in the general
population with µ = 30 days and σ = 6 days. You suspect that the use of insecticides has shortened
lives, and previous research in other states has shown that indeed their insecticide use leads to
shorter housefly lives. You wish to know whether that is true in Nevada. You will obtain a random
sample of 36 newly hatched houseflies and will record the length of their lives