statistics
posted by Shane on .
(population)
A normal distribution has a mean of 80 and a std dev of 20. For each of the following scores, indicate wheter the tail of the distribution is located to the right or left of the score, and find the proportion of the distribution located in the tail.
a.X=85, B.X=92, C. X=70 D. X=64

If the score is above the mean (ƒÊ), the tail will be to the right — and to the left, if below the mean.
The exact proportions can be found by using the Z score formula
Z = (x  ƒÊ)/SD
and looking those Z values up in a table in the back of your statistics text called something like "areas under the normal distribution."
I hope this helps. Thanks for asking.