The Cincinnati Enquirer, in its Sunday business supplement, reported that the mean number of hours worked per week by those employed full time is 43.9. The article further indicated that about one-third of those employed full-time work less than 40 hours per week.
a. Given this information and assuming that number of hours worked follows the nor- mal distribution, what is the standard deviation of the number of hours worked?
b. The article also indicated that 20% of those working full-time work more than 49 hours per week. Determine the standard deviation with this information. Are the two estimates of the standard deviation similar? What would you conclude?