Answer: 0.965
Step-by-step explanation:
Given : Water use in the summer is normally distributed with
Let X be the random variable that represents the quantity of water required on a particular day.
Z-score :
Now, the probability that a day requires more water than is stored in city reservoirs is given by:-
We can see that on comparing the above value to the given P(X > 350)= 1 - P(Z < b) , we get the value of b is 0.965.