On what percentage of the days were there problems?

[amy-lee]

I am having trouble with the question.


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


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

 

[royhaas]

The assumption of normality is not needed here, since the data is recorded as a percentage. Otherwise, you have to treat this as a normal sample with unknown parameters.