A standard IQ test has a mean of 98 and a standard deviation of 16. We want to be 99% certain that we are within 8 IQ points of the true mean. Determine the sample size
=NORMINV(0.01/2,0,1)
-2.575829304
=(2.58*16/8)^2
26.6256
round to 26.
-2.575829304
=(2.58*16/8)^2
26.6256
round to 26.