Question

(17.43) Athletes performing in bright sunlight often smear black eye grease under their eyes to reduce glare, thus increasing their sensitivity to visual contrast. Does eye grease work? In one study, 16 student subjects took a test of sensitivity to contrast after 3 hours facing into bright sun, both with and without eye grease. This is a matched pairs design. Here are the differences in sensitivity (sensitivity with eye grease minus sensitivity without eye grease): 0.07 0.64 -0.12 -0.05 -0.18 0.14 -0.16 0.03 0.05 0.02 0.43 0.24 -0.11 0.28 0.05 0.29 Data Set We want to know whether eye grease increases sensitivity to contrast, on average.

Answer 1

Fiven, n=16 -0.07, 0.64, -0.12,-0.05, -0.18,0.14,-0.16,0.03, 0.05,0.02, 0-43, 0.24,-0.11, 0-28,0.05,0.29 J = Ed = 1-62 = 0.1013 So= Ecd-" - 50-7634 Eld-a) ² 0.7684 T6-1 So= 0.2263 Null and Alternative hypothesis es, Hold =0 { حجم ولد : و the test statistics és za J-old - 0.1013 -0. 0.2263/ Salo 0.1013 0.0566 z = 1.79 The p-value is 0.037 Here, p-value <2 = 0.05 . We reject Null hypothesis. Conclusion :- We rejeet Null hypothesis, There sufficient evidence to conclude that eye grease increases sensitivity to contoost On average.