Assume that the mean life expectancy in the U.S. population is 78.7 years with a standard deviation of 10 years.

Given the above information, answer the following:

1) Calculate the probability of having an average life expectancy of less than 75 years among the sample of PH 92 students (n = 31). Draw the standardized normal distribution plot and identify the area under the normal curve, corresponding to the estimated probability value.

2) Assuming that life expectancy outcome in U.S. population follows a normal distribution, calculate the life expectancy in years for the top 5% of the U.S population.