Posted by chandler on .
30 new babies were born yesterday in the hospital. If the average weight of a new born is 7.5 pounds with a standard deviation of 2.1 pounds, what is the probability of the average weight for these 30 newborns is between 7.2 and 7.6 pounds. Remember, all probabilities are taken to 4 decimal places for this class

statistics 
PsyDAG,
Z = (scoremean)/SEm
SEm = SD/√n
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability between the two Z scores.