Thread: normal distribution?

I cant figure this out have been working on it for hours. Confused on part b.

1. Because of water shortages during a drought in a Canadian city, watering of lawns and gardens was permitted only from 06:00 to 09:00 and from 19:00 to 22:00. The peak consumption, as a percentage of total system capacity, was recorded each watering period for a week in July. Assume that the water consumption was normally distributed.

88, 95, 65, 94, 67, 94, 75,
93, 77, 100, 85, 100, 85, 100

a. Find the mean and the standard deviation.
µ = 87, σ = 11

b .Water pressure problems occur in the system after 99% capacity is reached. On what percentage of the days were there problems?

Originally Posted by Zora

I cant figure this out have been working on it for hours. Confused on part b.

1. Because of water shortages during a drought in a Canadian city, watering of lawns and gardens was permitted only from 06:00 to 09:00 and from 19:00 to 22:00. The peak consumption, as a percentage of total system capacity, was recorded each watering period for a week in July. Assume that the water consumption was normally distributed.

88, 95, 65, 94, 67, 94, 75,
93, 77, 100, 85, 100, 85, 100

a. Find the mean and the standard deviation.
µ = 87, σ = 11

b .Water pressure problems occur in the system after 99% capacity is reached. On what percentage of the days were there problems?

On three days consumption reached or exceeded 99% capacity, out of a total of seven days.

CB

Duplicate post. Thread closed.