In an experiment designed to study the effects of illumination level on task performance, subjects were required to insert a fine-tipped probe into the eyeholes of ten needles in rapid succession both for a low light level with black background and a higher level with a white background. Each data value is the time (sec) required to complete the task. Subject
1 2 3 4 5 6 7 8 9
Black 25.0 42.0 27.5 26.5 25.0 30.5 26.5 21.0 32.0
White 16.5 25.0 24.5 19.5 16.0 20.5 18.0 19.5 22.0
d = 8.5 17.0 3.0 7.0 9.0 10.0 8.5 1.5 10.0
Does the data indicate that the higher level of illumination yields a decrease of more than 5 sec in true average task completion time? Test the appropriate hypotheses using a level of significance level α = 0.05.
Parameter:
Null Hypothesis:
Alternative Hypothesis:
Test Statistic:
Reject Region:
Calculate:
Decision:
P-value: