Can you help with showing how to solve the questions in the pictures?

a) During the last week of the semester, students at a certain college spend on the average 4.5 hours using the school's computer terminals with a standard deviation of 1.6 hours. For a random sample of 64 students at that college, nd the probability that the average time spent using the school's computer terminals during the last week of semester is at least 5 hours. b) Suppose IQ's are normally distributed with a mean of 100 and a standard deviation of 15. What is the probability a randomly selected person has an IQ more than 110? c) An organization states that the upper 5% of the population is classied as genius. Someone that is classied as genius has an IQ of at least '.' _ Following a week-long hospital supervisory training program, 50 assistant hospital administrators made a mean score of 74 on a test administered as part of the evaluation of the training program with a sample standard deviation of 10. Use a 0.05 signicance level to test the claim that the population mean is greater than 70. State your conclusion using precise statistical language and complete sentences (state your conclusions In the context of the problem; relate your conclusions to the test statistic. critical value, p value and confidence interval)