Question

An alien empire came to Earth to brainwash people, the aliens claimed they brainwashed half of the population. A random sample of 500 people was selected, will a mean score of 245 being brainwashed. The standard deviation of 80 and assuming .50 as the alpha level. Are the alien’s claims correct?

Answer 1

Claim is that

Null and alternate hypothesis for the claim are

Given values are

population mean mu = 250

sample mean xbar = 245, population standard deviation (sigma) = 80

sample size n = 500

Using z distribution to find the p value for z = -1.40, we get

p value = 0.1616 > significance level 0.05, so we failed to reject the null hypothesis

Therefore, at 0.05 significance level, we have sufficient evidence to conclude that the alien’s claims correct