The pulse rates of 152 randomly selected adult males vary from a low of 37 bpm to a high of 117 bpm. Find the minimum sample size required to estimate the mean pulse rate of adult males. Assume that we want 95% confidence that the sample mean is within 3 bpm of the population mean. Complete parts (a) through (c) below.

a. Find the sample size using the range rule of thumb to estimate o.