2. Between 1971-1975, The CDC sampled white blood cells from 1,241 people aged 25-34, and found the average number of blood cells per microliter to be 4.5 with a standard deviation of 1.63 blood cells. (https://www.cdc.gov/nchs/data/series/sr_11/sr11_220.pdf) Assume that white blood cell count is normally distributed.

a. If one person aged from 25-34 is randomly selected, what is the probability that their white blood count is between 3.2 and 5 per microliter? (2 pts)

b. Let's say I took a group of 25 people and found their average white blood cell count. What kind of distribution can this be modelled after? Is this distribution approximately normal? Justify your answer below. (3 pts)

c. What is the probability that their white blood cell count is between 3.2 and 5 per microliter? (2 pts)