Question

what is the confidence interval estimate of the population mean μ?

• 1.33 mg/dl < μ < 9.53 mg/dl

(round to two decimal places as needed.)
what does the confidence interval suggest about the effectiveness of the treatment?
a. the confidence interval limits do not contain 0, suggesting that the garlic treatment did affect the ldl cholesterol levels.
b. the confidence interval limits do not contain 0, suggesting that the garlic treatment did not affect the ldl cholesterol levels.
c. the confidence interval limits contain 0, suggesting that the garlic treatment did not affect the ldl cholesterol levels.
d. the confidence interval limits contain 0, suggesting that the garlic treatment did affect the ldl cholesterol levels.

Explanation:

Step1: Analyze the confidence interval

The confidence interval is \(- 1.33\space mg/dL<\mu<9.53\space mg/dL\). We check if \(0\) is within this interval.
Since \(-1.33<0 < 9.53\), \(0\) is within the confidence interval.

Step2: Interpret the meaning of \(0\) in the confidence interval

If \(0\) is within the confidence interval for the mean change in LDL cholesterol (\(\mu\)), it suggests that there is no significant change (because a change of \(0\) means no net effect). In other words, the confidence interval limits contain \(0\), suggesting that the garlic treatment did not affect the LDL cholesterol levels.

Answer:

C. The confidence interval limits contain \(0\), suggesting that the garlic treatment did not affect the LDL cholesterol levels.