Directions: In 4-6, let the length of time to complete a certain test be normally distributed with // =95 and =15, each measured in minutes. Assume a subject who will take this test is randomly chosen. 4] Find the chances that the time this subject takes to complete the test is no more than 85 minutes. 5] Find the two times that separate the middle 70% of test times from both the lower 15% and the upper 15% of test times. 6] If 25 subjects are selected at random and given this test, what is the probability that their mean test time exceeds 100 minutes? 7] The ages of dollar bills in current circulation has an extremely skewed right distribution with mean 8 years and variance 36 years. If an SRS of size 64 dollar bills is chosen, find the probability that the mean age of this sample of dollar bills is between 9 and 10 years