Eye grease
Subject:StatisticsPrice: Bought3
Eye grease. Athletes performing in bright sunlight often smear black eye grease under their eyes to reduce glare. 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, with eye grease minus without eye grease:9
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
We want to know whether eye grease increases sensitivity on the average.
(a) What are the null and alternative hypotheses? Say in words what mean your hypotheses concern.
(b) Suppose that the subjects are an SRS of all young people with normal vision, that contrast differences follow a Normal distribution in this population, and that the standard deviation of differences is σ=0.22. Carry out a test of significance.
