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The highest recorder temperature during the month of July for a given year in De

ID: 3356125 • Letter: T

Question

The highest recorder temperature during the month of July for a given year in Death Valley, in California, has an approximately normally distribution with a mean of 123.8 degrees Fahrenheit with a standard deviation of 3.1 degrees Fahrenheit.

(a) What is the probability for a given year that the temperature never exceeds 120 degrees Fahrenheit in a given July in Death Valley?

(b) What is the probability that the temperature in Death Valley goes above 128 degrees Fahrenheit during July in a randomly chosen year?

Explanation / Answer

Mean is 123.8 and s is 3.1. z is given as (x-mean)/s

a) P(x<120)= P(z<(120-123.8)/3.1)=P(z<-1.23) or 1-P(z<1.23). from normal distribution table we get 1-0.8907=0.1093

b) P(x>128)=P(z>(128-123.8)/3.1)=P(z>1.35) or 1-P(z<1.35) or 1-0.9115=0.0885