A scientist is interested in the effect of time spent with parents and the number of hours youth spend watching television. The researcher knows that the average teen whose parents work outside the home spends 20 hours a week watching television. The population mean = 20 and the standard deviation of the distribution is equal to 5. Calculate the z-scores for the following individual times:
If X = 5, z = __________.
If X = 37, z = __________.
If X = 20, z = __________.