Question

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/mm3, what
is the probability that the counter would give a reading between 4,900,000 and 5,100,000?
(b) of 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 .98ì and 1.02ì?
(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?

Answer 1

hallo Im Asmaa I need help with part C.
part A & B I get it
this Q is from the book and the final answer of C is 1.24% as in the book but I need to find how I reach to this answer
thanks