SOLUTION: a company produces steel rods. THe lengths of the steel rods are normally distributed with a mean of 127.8-cm and a standard deviation of 1.8-cm. FInd P86 which is the length sep

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Question 1141589: a company produces steel rods. THe lengths of the steel rods are normally distributed with a mean of 127.8-cm and a standard deviation of 1.8-cm.
FInd P86 which is the length separating the shortest 86% rods from the longest 14%.
p86=______-cm
enter your answer as a number accurate to 1 decimal place
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
mean is 127.8
standard deviation is 1.8

z-score for 86 percent to the left of it is 1.08031934.

z-score formula is z = (x-m)/s

in this case:

z = 1.08031934
m = 127.8
s = 1.8.

z-score formula becomes 1.08031934 = (x-127.8)/1.8

solve for x to get x = 1.08031934 * 1.8 + 127.8 = 129.7445748.

round to 1 decimal point equals 129.7.

that should be your solution.