Posted by Becky on .
The weights of adult longtongued fruit bats are known to be normally distributed with a mean of 20.22 grams and a standard deviation of 3.23 grams. What is the probability that a randomly selected bat will:
a) weigh at most 15 grams?
b) weigh less than 30 grams?

Math 
PsyDAG,
Z = (scoremean)/SD
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions related to those Z scores.