Question

Answer all the STX Cmectio A production engineer finds that on an average mechanics working in a machine shop complete a certain task is 15 minutes. The time required to complete the task are approximately normally distributed with a standard deviation of 3 minutes. Compute the probabilities that the task is completed between 10 and 12 minutes Q1: me of middle

Answer 1

Q1.

At x = 10

z = (x - average completion time)/Standard deviation

or, z = (10-15)/3 = -1.67

At x = 12

z = (12-15)/3 = -1

Probabilities of task completing between 10 and 12 minutes = P(-1.67<z<-1)

= P(z<-1) - P(z<-1.67)

= 0.1587 - 0.0475

= 0.1112