Question

Assume the average amount of precipitation in a town of Texas, during the month of April is 4.0 inches (the World Almanac, 2000). Assume that a normal distribution applies and that the standard deviation is 0.5 inches. A month is classified as extremely wet if the amount of rainfall is in the upper 5% for the month. How much precipitation must fall in April for it to be classified as extremely wet?

		4.0 inches
		4.64 inches
		4.82 inches
		4.98 inches

Answer 1

X : the amount of rainfall

X ~ N (4,0.5)

let, a be the amount of rainfall  to be classified as extremely wet.

accoring to the problem,

[ in any blank cell of excel type =NORMSINV(0.95) ]

4.82 inches precipitation must fall in April for it to be classified as extremely wet.

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