A quick survey of peanut butter prices had standard deviation and mean of $0.26 and $3.68, respectively. Compute the area for a peanut butter jar costing less than $3.50.

Answer 1

The process on this type of question is to compute the Z score and then convert that over into a probability using either a calculator or statistical table. For the information given in this question that means taking

Z = (3.50 - 3.68) / 0.26 = -0.18 / 0.26 = -0.692

Then using a Z table, that should correspond to a probability/area value of 0.244