Astudy is made of incomes among full-time workers age 25–54 in a certain town. a simple random sample is taken, of 250 people with high school degrees: the sample average income is $30,000 and the sd is $25,000. another simple random sample is taken, of 250 people with college degrees: the sample average income is $50,000 and the sd is $40,000. 1. is the difference in averages real, or due to chance?