A manufacturer knows that their items have a normally distributed lifespan, with a mean of 15 years, and standard deviation of 3.7 years. If you randomly purchase 22 items, what is the probability that their mean life will be longer than 13 years?

The probability that their mean life will be longer than 13 years = .9943 or 99.43%

Step-by-step explanation:

Given -

Mean = 15 years

Standard deviation = 3.7 years

Sample size ( n ) =22

Let be the mean life of manufacturing items

the probability that their mean life will be longer than 13 years =

=        

                    =  

                    =       Using Z table

                    = 1 - .0057

                    =  .9943

add an !

step-by-step explanation:

maximum area = xy = (16)(32) = 512 ft2

to maximize the area of the garden, the side of the fence parallel to the side of the house should be 32 ft long, and the other two sides should both have length 16 ft.'

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