If Tennant Creek Town’s daily water demand is approximately normally distributed with a mean of 5 ml and a standard deviation of 1.25ml:
a) Estimate the number of days in a (365 day) year on which daily consumption is:
i. 50% or more greater than the mean. [1 Marks]
ii. within two standard deviation of the mean. [1 Marks]
iii. below the first quartile level of demand. [1 Marks]
b) If the water supply authority decides to save money by setting supply capacity to a level adequate to satisfy daily demand on 95% of all days at what level should capacity be set?