In 2001, the U. Department of Labor reported the average hourly earnings for U. production workers to be $14.32 per hour (The World Almanac 2003).

In 2001, the U.S. Department of Labor reported the average hourly earnings for U.S. production workers to be $14.32 per hour (The World Almanac 2003). A sample of 60 production workers during 2003 showed a sample mean of $14.68 per hour. Assuming the population standard deviation = $1.60, can we conclude that an increase occurred in the mean hourly earnings since 2001? Use = .05.