More Calculations Involving The Normal Distribution - Finding Probabilities

Suppose we have a distributionWe will findusing the diagram on the left.

This corresponds to a probability of 0.6915 hence

Now we will find illustrated by the diagram on the left. Ignoring the minus sign we go to the normal distribution tables and look for the probability corresponding to finding 0.7422. Because we had a negative value ofwe subtract this from 1. We have found Because the probabilities in the tables are all of the formWe subtract this value from 1 again to obtain

Now we use