X score is normally distibuted with mean 90 and standard deviation 23 Find:
A-the probability of a score between 76 and 117
b-probability that the mean score of a sample of n=64 is greater than 97
I am getting for A) .608421 as the probability.
For B) you use the central Limit Theorem. Please try that now.
In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
A number by itself is useful, but it is far more useful to know how accurate or certain that number is.