Posted by Anonymous on .
87,89,90,90,98,99,99,101,102,103,104
Within how many standard deviations of the mean is the value 102?

Statistics 
PsyDAG,
Find the mean first = sum of scores/number of scores
Subtract each of the scores from the mean and square each difference. Find the sum of these squares. Divide that by the number of scores to get variance.
Standard deviation = square root of variance
Z score is your score in terms of standard deviations (SD).
Z = (scoremean)/SD
I'll let you do the calculations.