Results for a 1997 survey of about 25,000 male nonfarm wage and salary workers were published in the Monthly Labor Review in 1998. Hours worked in the week prior to the survey were found to have mean 42.66 and standard deviation 12.46.
a. Find the standardized sample mean weekly hours worked, if population mean was equal to 40.
b. Based on your answer to part (a), what can we assert about the population mean hours worked by male nonfarm wage and salary workers?