Assume that the mean systolic blood pressure of normal adults is 120 millimeters of mercury (mm Hg) and the standard deviation is 5.6. Assume the variable is normally distributed.

a) if an individual is selected find the probability that the individual's pressure will be less than 121.8mm Hg ( provide an answer with 4 decimal places)

b) if a sample of 30 adults is randomly selected find the probability that the sample mean will be less than 121.8 mm Hg ( provide an answer with four decimal places)