33. In Chapter 15, Problem 21, p. 437, an experiment was conducted to determine whether sleep loss affects the ability to maintain sustained attention.

Fifteen individuals were randomly divided into the following three groups of fi ve subjects each:

group 1, which got the normal amount of sleep

(7–8 hours); group 2, which was sleep-deprived for 24 hours; and group 3, which was sleepdeprived for 48 hours. All three groups were tested on the same auditory vigilance task. Half-second tones spaced at irregular intervals were presented over a 1-hour duration. Occasionally, one of the tones was slightly shorter than the rest. The subject’s task was to detect the shorter tones. The following percentages of correct detections were observed:

In that problem, the normality assumption was assumed met, and the analysis was conducted using the F test. For this problem, assume the F test cannot be used because of an extreme violation of the normality assumption. Analyze the data with the Kruskal–Wallis test, using 0.05.
cognitive

Normal Sleep-Deprived Sleep-Deprived Sleep for 24 Hours for 48 Hours 85 60 60 60 83 58 48 76 76 38 64 52 47 75 63 50