Life Expectancies In a study of the life expectancy of 500 people in a certain geographic region, the mean age at death was 72.0 years and the standard deviation was 5.3 years. If a sample of 50 people from this region is selected, find the probability that the mean life expectancy will be less than 71.4 years. Round intermediate z-value calculations to 2 decimal places and round the final answer to at least 4 decimal places. P(X < 71.4)=.