Question

A sample of 800 computer chips revealed that 80% of the chips do not fail in the first 1000 hours of their use. The company's promotional literature claimed that over 76% do not fail in the first 1000 hours of their use. Is there sufficient evidence at the 0.02 level to support the company's claim? State the null and alternative hypotheses for the above scenario.

Answer 1

we have

Null hypothesis:- p = 0.76  

Alternate hypothesis:- (More than 76% dont fail in the first 1000 hours of their use)

calculation for z test statistic

z =

setting the values

we get

z =

Calculation for P value corresponding to the z value

we get

So, the p value is 0.004, which is less than 0.02 significance level

Thus, the p value is significant and we can reject the null hypothesis

So, we can conclude that there is enough evidence to support the claim that over 76% do not fail in the first 1000 hours of their use.