From the way you posted, I cannot understand your data. However….
Z = (score-mean)/SD
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability for each Z score.
The age distribution of students at a community college is given below.
Age (years) Number of students (f)
11)
Over 35 26
1103
A student from the community college is selected at random. Find the conditional probability that the student is at most 35 given that he or she is at least 26.
1 answer