Question

A manufacturer of TV sets claims that at least 98% of its TV sets can last more than 10 years without needing a single repair. In order to verify and challenge this claim, a consumer group randomly selected 800 consumers who had owned a TV set made by this manufacturer for 10 years. Of these 800 consumers, 60 said that their TV sets needed some repair at least once. a. Is there significant evidence showing that the manufacturer’s claim is false? Test using α = 0.01. b. Do the data support that the manufacturer’s actual no-repair rate does not even reach 94%? Use α = 0.01. need to know how the variance is found step by step

Answer 1

a)

for test statistics falls in rejection region, we reject null hypothesis and conclude that the manufacturer’s claim is false

b)

as confidence interval contains 0.94 (94%) as a plausible value for population percentage therefore does not support that the manufacturer’s actual no-repair rate does not even reach 94%