According to a particular marketing​ corporation, the per capita consumption of bottled water is 3.8 gallons per month. Assume the standard deviation for this population is 0.85 gallons per month. Consider a random sample of 36 people.

a. What is the probability that the sample mean will be less than 3.6 gallons per​ month?
b. What is the probability that the sample mean will be more than 4.1 gallons per​ month?
c. Identify the symmetrical interval that includes 83​% of the sample means if the true population mean is 3.8 gallons per month.