A company that makes cola drinks states that the mean caffeine per 12-ounce bottle of cola is 35 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 32.8 milligrams with a standard deviation of 7.9 milligrams. At a=0.05, can you reject the company’s claim?
a) Identify H0 and Ha
b) Find the critical value(s) (round to two decimal places as needed.
A. The critical value is
B. The critical values are ±1.96
c) Find the standardized test statistic. Z= (round to two decimal places as needed)
d) Decide whether to reject or fail to reject the null hypothesis.
A. since z is the rejection region, fail to reject the null hypothesis.
B. since z is not in the rejection region, fail to reject the null hypothesis.
C.since z is in the rejection region, reject the null hypothesis.
D.since z is not in the rejection region, reject the null hypothesis.
e)At the 5% significance level, there (is or) enough evidence to (support or) the companys claim that the mean caffeine content per 12-ounce bottle of cola (is different from, , is greater than, is less than) milligrams.
