When red blood cells are counted using a certain electronic counter, the standard deviation (SD) of repeated counts of the same blood specimen is about .8% of the true value, and the distribution
of repeated counts is approximately normal. For example, this means that if the true value is 5,000,000 cells/mm3, then the SD is 40,000.

a. If the true value of the red blood count for a certain specimen is 5,000,000 cells/mm^3, what is the probability that the counter would give a reading between 4,900,000 and 5,100,000?
b. If the true value of the red blood count for a certain specimen is ì, what is the probability that the counter would give a reading between .98µ and 1.02µ?
c. A hospital lab performs counts of many specimens every day. For what percentage of these specimens does the reported blood count differ from the correct value by 2% or more?