The pulse rates of 154 randomly selected adult meals vary from a low of 40 bpm to a high of 116 bpm find the minimum sample size required to estimate the main pulse rate of adult males assume that we...

The pulse rates of 154 randomly selected adult meals vary from a low of 40 bpm to a high of 116 bpm find the minimum sample size required to estimate the main pulse rate of adult males assume that we want 99% confidence that the sample mean is within 2 bpm of the population mean.
A. Find the sample size using the range rule of thumb to estimate standard deviation.
B. Assume that standard deviation equals 12.4 bpm based on the value as equals 12.4 bpm from the sample of one her new room 54 male pulse rates.
n=?