A researcher is interested in whether union workers earned significantly higher wages than nonunion workers last year. She interviewed 12 union workers and 15 nonunion workers, and their wages are shown below. Test the null hypothesis of no difference between the wages of union workers and nonunion workers.
Union Nonunion
$16.25………………………. $11.20
15.90………………………. 10.95
14.00………………………. 13.50
17.21………………………. 15.00
16.00………………………. 12.75
15.50………………………. 11.80
18.24………………………. 13.00
16.35………………………. 14.50
13.90………………………. 10.75
15.45………………………. 15.80
17.80………………………. 13.00
19.00………………………. 11.65
……………………….……10.50
……………………………..14.00
…………………………….15.40