Question: Assume that the mean systolic blood pressure of normal adults is 122 milliliters of mercury with a standard deviation of 5.6 milliliters. Assuming a normal distribution, what is the probability that:
a) An individual teacher will have a pressure between 120 and 121.8 milliliters?
b) That a sample of 30 adults will have a pressure between 120 and 121.8 milliliters?
c) Explain the difference in the answers for parts a and b.