Because of the rising costs of industrial accidents, many chemical, mining, and manufacturing firms have instituted safety courses. Employees are encouraged to take these courses designed to heighten safety awareness. A company is trying to decide which one of two courses to institute. To help make a decision eight employees take course 1 and another eight take course 2. Each employee takes a test which is graded out of a possible 25. The safety test results are shown below. Assume that the scores are normally distributed. Do these data provide sufficient evidence at the 5% level of significance to infer that the marks from course 2 are higher than from course 1?

course 1

14

21

17

14

17

19

20

16

Course 2

20

18

22

15

23

21

19

15

What is the appropriate test to perform?

• Paired test.H₀:_D<0versusH_a:_D=0
• Paired test.H₀:_D=0versusH_a:_D<0
• Two-sample test.H₀:₁=₂versusH_a:₁₂
• Paired test.H₀:_D=0versusH_a:_D0
• Two-sample test.H₀:₁=₂versusH_a:₁>₂
• Two-sample test.H₀:₁=₂versusH_a:₁<₂
• Paired test.H₀:_D=0versusH_a:_D>0
• Two-sample test.H₀:₁<₂versusH_a:₁=₂