The Bureau of Labor Statistics reported that the average yearlyincome of dentists in the year 2012 was $110,000.  Asample of 81 dentists, which was taken in 2013, showed an averageyearly income of $120,000.  Assume the standard deviationof the population of dentists’ incomes in2013 is $36,000.
Test the hypotheses at 95% confidence. |
