10.43 According to published reports, practice un- der fatigued conditions distorts mechanisms that gov- ern performance. An experiment was conducted using 15 college males, who were trained to make a continu- ous horizontal right-to-left arm movement from a mi- croswitch to a barrier, knocking over the barrier co- incident with the arrival of a clock sweephand to the 6 o'clock position. The absolute value of the differ- ence between the time, in milliseconds, that it took to knock over the barrier and the time for the sweephand to reach the 6 o'clock position (500 msec) was recorded. Each participant performed the task five times under prefatigue and post fatigue conditions, and the sums of the absolute differences for the five performances were recorded. Absolute Time Differences Subject Prefatigue Postfatigue 1 158 91 2 92 59 3 65 215 4 98 226 5 33 223 6 89 91 148 92 8 58 177 9 142 134 10 117 116 11 74 153 12 66 219 13 109 143 14 57 164 15 85 100 An increase in the mean absolute time difference when the task is performed under postfatigue conditions would support the claim that practice under fatigued conditions distorts mechanisms that govern perfor- mance. Assuming the populations to be normally dis- tributed, test this claim.