Question

You have been assigned to test the hypothesis that the average number of hours per week that an American works is higher than the average number of hours per week that a Swede works. The following data summarizes the sample statistics for the number of hours worked per week for workers in each country. Assume that the population variances are unequal.

	American	Swede
Sample mean	32.7 hours	28.2 hours
Sample size	15	12
Sample standard deviation	5.1 hours	6.0 hours

If Population 1 is defined as American workers and Population 2 is defined as Swedish workers, the correct hypothesis statement for this hypothesis test would be

		H0: μ1 - μ2 = 0; H1: μ1 - μ2 ≠ 0
		H0: μ2 - μ1 = 0; H1: μ2 - μ1 > 0
		H0: μ1 - μ2 = 0; H1: μ1 - μ2 > 0
		H0: 2 - 1 = 0; H1: 2 - 1 < 0

Answer 1

According to the question, the researcher wants to test the hypothesis that the average number of hours per week that an American works is more than the average number of hours per week that a Swede works. Moreover, the American workers are defined as population 1 and the Swede workers are defined as population 2. To check whether the average number of hours per week that an American works is more than the average number of hours per week that a Swede works or not, the null and alternative hypotheses are defined as follows: H:14 - Mz = 0 H:M - , > 0 Here, 14 is the population average number of hours per week that an American works, and y, is the population average number of hours per week that a Swede works. Hence, the null and alternative hypotheses are, HO:/4 - = 0 H:/-u, >0