Biologists studying the healing of skin wounds measured the rate at which new cells closed a cut made in the skin of an anesthetized newt. here are data from a random sample of 18 newts, measured in micrometers (millionths of a meter) per hour: 29, 27, 34, 40, 22, 28, 14, 35, 26, 35, 12, 30, 23, 18, 11, 22, 23, 33

(a) create a qq plot of the data. do you think it is reasonable to assume that the population distribution is normal? explain your answer. (there isn’t a unique "right" answer.)

(b) regardless of your answer to (a), assume the population distribution is normal and use that assumption to create a 90% ci for µ, the population mean rate. (use a calculator to find ¯x and s and then use the formula provided in class to prepare for exams. then check your answer with r if you wish.)