I have no idea how to start either part of this question

5. Sleep Patterns. (15 pts) In a sleep study, 75 randomly selected subjects had 8.5 hours of sleep per night on average. While constructing a 95% confidence interval around that sample mean of 8.5, the researchers found the margin of error to be 2.72. a. Given this information, what was the standard deviation associated with the sample mean of 8.5? (10 pts) b. Let us say that on average most people in the general population spend 6.2 hours sleeping. Can we say with 95% confidence that the sample mean above is significantly different from the population mean? (5 pts)