Question

A company that makes cola drinks states that the mean caffeine content per​ 12-ounce bottle of cola is 55 milligrams. You want to test this claim. During your​ tests, you find that a random sample of thirty​ 12-ounce bottles of cola has a mean caffeine content of 53.7 milligrams. Assume the population is normally distributed and the population standard deviation is 6.9 milligrams. At alphaequals0.09​, can you reject the​ company's claim?

Answer 1

This hypothesis test is a two tailed test .

The null and alternative hypothesis is

H₀ : = 55

H_a : 55

Test statistic = z

= ( - ) /    / n

= (53.7 - 55) / 6.9 / 30

Test statistic = -1.032

P-value = 0.3021

P-value >

Fail to reject the null hypothesis .

Can not reject the​ company's claim .