A company has been able to restrict the use of electrical power through energy conservation measures. The monthly use is known to be normal with a mean of 60,000 kWh (kilowatt-hour) and a standard deviation of 400 kWh.
(a) What is the probability that the monthly consumption will be less than 59,100 kWh?
(b) What is the probability that the monthly consumption will be between 59,000 and 60,300 kWh?
(c) The capacity of the utility that supplies this company is 61,000 kWh. What is the probability that demand will not exceed supply by more than 100 kWh?