Question

3. A psychologist wants to determine the effect of instructions on the time required to solve a mechanical puzzle. Each of 20 volunteers is given the same mechanical puzzle to be solved as rapidly as possible. Before the task, the subjects are randomly assigned in equal numbers to receive two different sets of instructions. One group is told that their task is difficult (M₁), and the other group is told that their task is easy (M₂). The score for each subject reflects the time in minutes required to solve the puzzle. Use a t-test to evaluate the null hypothesis at the .05 level of significance.

                                     Solution Times

"Difficult" Task                                            "Easy" Task

5                                                                     13

20                                                                    6

7                                                                     6

23                                                                    5

30                                                                    3

24                                                                    6

9                                                                     10

8                                                                     20

20                                                                    9

12                                                                    12

___                                                                  ____

Answer 1