Question

A company produces steel rods. The lengths of the steel rods are normally distributed with a mean of 207.9-cm and a standard deviation of 1.5-cm. For shipment, 26 steel rods are bundled together.

Find P₂₆, which is the average length separating the smallest 26% bundles from the largest 74% bundles.

Answer 1

= 207.9

= 1.5

n = 26

SE = /

= 1.5/

=0.2942

26% corresponds to area = 0.50 - 0.26 = 0.24

Table of Area Under Standard Normal Curve gives Z = - 0.645

So,

Z = - 0.645 = ( - 207.9)/0.2942

So,

= 207.9 - (0.645 X 0.2942)

= 207.7102

So,

Answer is:

207.7102