Charanka Solar Park in India reports that it produces an average of 16,400 kilowatt hours (kwh) of electricity per day, with a standard deviation of 2200 kwh.If this electrical output has a normal distribution we would expect that on 95% of the days, the day's output would be between 12,090 kwh and how many kwh.
A)18,600
B)20,710
C)16,320
D)19,400
E)15,350

Question

Quizplus · Accepted Answer

Using the 95% confidence interval for a normal distribution, we calculate the range as the mean ± 1.96 * standard deviation. Given the mean is 16,400 kwh and the standard deviation is 2,200 kwh, the upper limit is calculated as 16,400 + (1.96 * 2,200) = 16,400 + 4,312 = 20,712 kwh. The closest option to this calculated value is 20,710 kwh.

Charanka Solar Park in India Reports That It Produces an Average