Question

Assume that a simple random sample has been selected from a normally distributed population and test the given claim. Identify the null and alternative hypotheses, test statistic, P-value, critical value(s), and state the final conclusion that addresses the original claim. A simple random sample of 25 filtered 100mm cigarettes is obtained, and the tar content of each cigarette is measure. The sample has a mean of 19.4 mg and a standard deviation of 3.52 mg. Use a 0.05 significance level to test the claim that the mean tar content of filtered 100 mm cigarettes is less than 21.1 mg, which is the mean for unfiltered king size cigarettes. What do the results suggest about the effectiveness of the filters? What are the hypotheses? Identify the test statistic. Identify the P-value Identify the critical value(s). State the final conclusion that addresses the original claim. A. Fail to reject H0. There is insufficient evidence to support the claim that the mean tar content of filtered 100 mm cigarettes is less than 21.1 mg. B. Reject H0. There is sufficient evidence to support the claim that the mean tar content of filtered 100 mm cigarettes is less than 21.1 mg. C. Fail to reject H0. There is sufficient evidence to support the claim that the mean tar content of filtered 100 mm cigarettes is less than 21.1 mg. D. Reject H0. There is insufficient evidence to support the claim that the mean tar content of filtered 100 mm cigarettes is less than 21.1 mg. What do the results suggest, if anything, about the effectiveness of the filters? A. The results are inconclusive because the sample size is less than 30. B. The results suggest that the filtered cigarettes have the same tar content as unfiltered king size cigarettes. C. The results do not suggest that the filters are effective. D. The results suggest that the filters are effective. E. The results suggest that the filters increase the tar content.

Answer 1

1) Option A: Fail to reject H0. There is insufficient evidence to support the claim that the mean tar content of filtered 100 mm cigarettes is less than 21.1 mg.

2)Option D: The results suggest that the filters are effective

Explanation:

We are given;

Sample size; n = 25

Sample mean; x' = 19.4 mg

Standard deviation; s = 3.52 mg

Population mean; μ = 21.1 mg

Let's state the hypotheses;

Null Hypothesis;H0: μ = 21.1 mg

Alternative Hypothesis; Ha; μ < 21.1 mg

Now, since sample size is less than 30,we will use a t-test.

Thus;

t = (x' – μ)/[s/√(n)]

t = (19.4 - 21.1)/(3.52/√25)

t = -2.415

Using an online p-value from t-score calculator as attached with the parameters t = -2.415, DF = 25 - 1 = 24, significance level = 0.05, one tailed, we have;

The p-value is 0.011885.

The calculated p-value is less than the significance level of 0.05. Thus, we will fail to reject the null hypothesis and conclude that there is insufficient evidence to support the claim that the mean tar content of filtered 100 mm cigarettes is less than 21.1 mg.