Following are the results of a wage study for nurses: Group Mean wage Standard deviation Sample size Union $20.75 2.25 40 Nonunion $19.80 1.90 45 a. At the 5% significance level, is reasonable to conclude that union nurses earn more? b. What is the p-value of the test. Solution t= (20.75-19.80)/2.25^2/40 +1.90^2/45 t= 2.09 Looking at a t table with degrees of freedom 40 we get .02.