Reducing hand stress with patient transfer devices. Refer to the Human Factors (November 2019) study of frictionreducing patient-transfer devices, Exercise 9.57 (p. 551). Recall that four different devices were tested in a lateral transfer task (pulling a patient between two hospital stretchers): (1) draw sheet; (2) friction-reducing repositioning sheet; (3) slide board; and (4) air-assisted device. Each in a sample of 20 professional caregivers performed the task using each of the four devices in random order. The dependent variable recorded during each task was hand pull force (measured in Newtons). The data (simulated, based on information provided by the study) are listed in the table.

a. What nonparametric test will allow you to compare the distributions of hand pull force for the four patienttransfer devices?

b. For each caregiver, rank the hand pull force values of the four devices.

c. Sum the ranks for the four devices, then use the rank sums to compute the test statistic.

d. At a = .05, find the rejection region for a test to compare the hand pull force distributions for the four devices.

e. Make the proper conclusion, in the words of the problem. Do the results agree with the parametric ANOVA conducted in Exercise 9.57? Caregiver Draw Sheet Repositioning Sheet Slide Board Air-assisted Device 1 127 126 103 40 2 130 132 96 47 3 118 109 86 30 4 120 111 95 35 5 133 117 113 34 6 123 118 92 41 7 114 110 100 43 8 125 123 99 44 9 135 137 117 41 10 119 115 120 42 11 135 140 119 46 12 144 136 113 54 13 134 118 105 41 14 123 115 108 40 15 130 113 99 45 16 131 130 100 42 17 141 132 109 54 18 137 124 96 44 19 127 128 103 43 20 128 120 105 40