Challenge No. 4:

Based on the published reports, working under fatigued conditions distorts body mechanisms and affects performance in the Joy Lands including game stations, dining spots, and many more. An experiment was conducted using 15 males working in the famous theme park, who were trained to make a continuous horizontal arm movement from a barrier, knocking over the barrier coincident with the arrival of a clock sweephand to the 6 oclock position. The absolute value of the difference between the time, in milliseconds, that it took to knock over the barrier and the time for the sweephand to reach the 6 oclock position (500 msec) was recorded. Each participant performed the task five times under postfatigued conditions, and the sums of the absolute differences for the five performances were recorded.

	Absolute time differences
Subject	Postfatigue
1	91
2	59
3	215
4	226
5	223
6	91
7	92
8	177
9	134
10	116
11	153
12	219
13	143
14	164
15	100

An increase in the mean absolute time difference when the task is performed under postfatigued conditions would support the claim that the postfatigued conditions distorts body mechanisms when the mean value is greater than 140 msec. Assuming the populations to be normally distributed, test this claim. (4 marks)