A special diet is intended to reduce the cholesterol of patients at risk of heart disease. If the diet is effective, the target is to have the average cholesterol of this group be below 200. After six months on the diet, an SRS of 50 patients at risk for heart disease had an average cholesterol (of sample)= 192, with standard deviation s=21. Assume the distribution of the cholesterol for patients in this group is approximately Normal with mean (µ).
A 95% confidence interval for the average cholesterol level of all similar patients who have been on the diet for 6 months is
| A. |
143 ± 21. |
| B. |
143 ± 7.78. |
| C. |
143 ± 8.14. |
| D. |
143 ± 1.54. |
Calculate the p-value for the one sample t test. Make a conclusion based on the p-value given a significance level ?=0.02.