In: Statistics and Probability
A consumer research organization states that the mean caffeine content per 12-ounce bottle of a population of caffeinated soft drinks is 37.8 milligrams. You find a random sample of 48 12-ounce bottles of caffeinated soft drinks that has a mean caffeine content of 35.2 milligrams. Assume the population standard deviation is 12.5 milligrams. At α=0.05, do you support or reject the organization’s claim using the test statistic?
Claim is alternative, reject the null and reject claim as test statistic (-1.44) is in the rejection region defined by the critical value (-1.64)
Claim is alternative, fail to reject the null and support claim as test statistic (-1.44) is not in the rejection region defined by the critical value (-1.64)
Claim is null, fail to reject the null and support claim as test statistic (-1.44) is not in the rejection region defined by the critical value (-1.96)
Claim is null, reject the null and reject claim as test statistic (-1.44) is in the rejection region defined by the critical value (-1.96)
Solution-
Given that-
A consumer research organization states that the mean caffeine content per 12-ounce bottle of a population of caffeinated soft drinks is 37.8 milligrams. You find a random sample of 48 12-ounce bottles of caffeinated soft drinks that has a mean caffeine content of 35.2 milligrams. Assume the population standard deviation is 12.5 milligrams.
Answer is-
Claim is null, fail to reject the null and support claim as test statistic (-1.44) is not in the rejection region defined by the critical value (-1.96)
◆ Test Calculation and Results-
Population Standard deviation is given so we use z -test to test our claim.
Our claim is null Hypothesis.