What is the chance HRC finds a sample mean between $477 and $527?

Question

Human Resource Consulting (HRC) surveyed a random sample of 60 Twin Cities construction companies to find information on the costs of their health care plans. One of the items being tracked is the annual deductible that employees must pay. The Minnesota Department of Labor reports that historically the mean deductible amount per employee is $502 with a standard deviation of $100 What is the chance HRC finds a sample mean between $477 and $527?

Answer 1

0.1974 or 19.74% of the deductibles would lie between $477 & $527.

 

Obtained from DISTR command on TI-83:  normalcdf(477,527,502,100) ; these four parameters are the a & b scores on the X line, and the μ and σ values of a normal distribution)