statistics
posted by Abby .
Scores on the ACT test are normally distributed with a mean of 21.1 and a standard deviation of 4.8. If one ACT score is randomly selected, find the probability that it is greater than 20.

Find the zscore.
http://www.ehow.com/how_4555631_calculatezscorestatistics.html
Then look up the p value on the z table.