8. (6 points) Daily observations for a period of 144 days have been conducted about the number of candy bars sold from a vending machine. Using these observations, the sample mean is calculated to be 258 and the sample standard deviation is calculated to be 60 . (a) (2 points) What is the probability that the sample mean number of candy bars sold for the 144-day period is less than 273 ? (b) (2 points) What is the probability that the total number of candy bars sold for the 144-day period is greater than 34,992 but less than 37,872 ? (c) (2 points) If the profit per candy bar is 5 cents, what is the probability that the average profit per day over the 144-day period is at least $12.65