If scores are normally distributed with a mean of 3.06 and a standard deviation of 0.84, what percent of the scores is: (a) greater than 3.9? (b) less than 2.22? (c) between 2.22 and 3.9?
Z = (score-mean)/SD
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions related to that Z scores.