Watch your cholesterol: A sample of 316 patients between the ages of 38 and 82 were given a combination of drugs ezetimibe and simvastatin. They achieved a mean reduction in total cholesterol of 0.95 millimole per liter. Assume the population standard deviation is =σ0.19.Part: 0 / 30 of 3 Parts CompletePart 1 of 3(a) Construct a 99% confidence interval for the mean reduction in total cholesterol in patients who take this combination of drugs. Round the answer to at least two decimal places.A 99% confidence interval for the mean reduction in cholesterol is <<μ.
Question
Watch your cholesterol: A sample of 316 patients between the ages of 38 and 82 were given a combination of drugs ezetimibe and simvastatin. They achieved a mean reduction in total cholesterol of 0.95 millimole per liter. Assume the population standard deviation is =σ0.19.Part: 0 / 30 of 3 Parts CompletePart 1 of 3(a) Construct a 99% confidence interval for the mean reduction in total cholesterol in patients who take this combination of drugs. Round the answer to at least two decimal places.A 99% confidence interval for the mean reduction in cholesterol is <<μ.
Solution
To construct a 99% confidence interval for the mean reduction in total cholesterol, we will use the formula for a confidence interval:
CI = x̄ ± Z * (σ/√n)
where:
- x̄ is the sample mean
- Z is the Z-score corresponding to the desired confidence level (for a 99% confidence level, the Z-score is approximately 2.576)
- σ is the population standard deviation
- n is the sample size
Given:
- x̄ = 0.95 (mean reduction in total cholesterol)
- σ = 0.19 (population standard deviation)
- n = 316 (sample size)
Substituting these values into the formula, we get:
CI = 0.95 ± 2.576 * (0.19/√316)
To simplify further, calculate the standard error (σ/√n):
Standard Error = 0.19/√316 = 0.0107 (rounded to four decimal places)
Substitute the standard error back into the confidence interval formula:
CI = 0.95 ± 2.576 * 0.0107
Calculate the margin of error (Z * Standard Error):
Margin of Error = 2.576 * 0.0107 = 0.0276 (rounded to four decimal places)
Finally, calculate the confidence interval:
CI = 0.95 ± 0.0276
So, the 99% confidence interval for the mean reduction in total cholesterol in patients who take this combination of drugs is (0.9224, 0.9776), rounded to four decimal places.
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