Question

otorola discovered that the average defect rate for parts produced on an assembly line varies from run-to-run and is approximately normally distributed with a mean equal to 3 defects per million. Assume that the goal at Motorola is for the average defect rate to vary no more than 1.5 standard deviations above or below the mean of 3. How likely is it that the goal will be met?.

Answer 1

You are looking for the area under a normal curve between -1.5 and 1.5 standard deviations.

Use a calculator to find this area

or Use a z-table.

Answer 2

0.8664