SOLUTION: Suppose that the replacement times for washing machines are normally distributed with a mean of 8.7 years and a standard deviation of 1.6 years. Find the replacement time that sep

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Question 437352: Suppose that the replacement times for washing machines are normally distributed with a mean of 8.7 years and a standard deviation of 1.6 years. Find the replacement time that separated the top 18% of washing machines from the bottome 82%
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi

Suppose that the replacement times for washing machines are normally distributed 

with a mean of 8.7 years and a standard deviation of 1.6 years

Find the replacement time that separated the top 18% of washing machines 

from the bottome 82%   P (x < 82%)  then z = .9154    | NORMSINV(0.82) 

*Note: z+=+blue%28x+-+mu%29%2Fblue%28sigma%29

   .9154(1.6) + 8.7 = x

           10.1646 = x