Let be a random variable representing the amount of water in litres used (lavatory, drinking and hand washing) by individual staff at JKUAT per day.

Let be a random variable representing the amount of water in litres used (lavatory, drinking and hand washing) by individual staff at JKUAT per day. Suppose that and that a sample size 45 is taken from the distribution.

Find the probability that if a staff member is randomly picked from the sample, he/she consumes between 14 and 16 litres.                                                                      

What is the probability that the mean consumption of this sample exceeds 21 litres?