The U.S. Bureau of Labor Statistics’ most current figures indicate the average wage for construction workers was about $18.08 an hour. Its survey suggests that construction wages can vary widely. Hartford, Connecticut, wages are approximately 38% larger, and Brownsville, Texas, wages are about 30% lower than the national average. A sample of 25 construction workers in San Antonio, Texas, yielded an average wage of $13.27 and a standard deviation of $1.46.
a. Estimate the standard deviation of the nation’s construction wages.
b. Does it appear that both the average and the standard deviation of the construction workers’ wages in San Antonio are smaller than those of the nation as a whole? Use hypotheses tests and a significance level of 0.05 to make your determination.