A marketing firm asked a random set of married and single men how much they were willing to spend on a vacation. Is there sufficient evidence at α = 0.05 to conclude that is there a difference in the two amounts?
Married men Single men
Sample size 50 40
Sample mean $640 $665
Population variance 5700 9100
a. No, because the test value -0.07 is inside the critical region
-1.96 < z < 1.96 .
b. No, because the test value -1.35 is inside the critical region
-1.96 < z < 1.96 .
c. No, because the test value -1.60 is inside the critical region
-1.96 < z < 1.96 .
d. No, because the test value -1.60 is outside the critical region
-1.96 < z < 1.96 .