A doctor wants to estimate the HDL cholesterol of all 20 to 29 year old females. how many subjects are needed to estimate the mean HDL cholesterol within 3 points with 99% confidence assuming s=14.6 based on earlier studies? Suppose the doctor would be content with 90% confidence. How does the decrease in confidence affect the sample size required? A 99% confidence level requires ___ subjects

We have presented a confidence interval (CI) for the difference, μ1 − μ2, between two population means. Interpret each confidence interval. 99% CI is from −10 to 5.

In a sample of 500 Canadians, it was found that 400 people preferred apple products. In a sample of 700 Americans it was found that 600 preferred apple products. Is the proportion Canadians who prefer apple products less than Americans. 1. Construct 95% confidence interval for difference of proportions. 2. From the confidence interval, do you think that the proportion of Canadians who prefer apple products is different from Americans.

A doctor wants to estimate the mean HDL cholesterol of all 20- to 29-year-old females. How many subjects are needed to estimate the mean HDL cholesterol within 3 points with 99% confidence assuming s = 14.7 based on earlier studies? Suppose the doctor would be content with 95% confidence. How does the decrease in confidence affect the sample size required? Click the icon to view a partial table of critical values. subjects. (Round up to the nearest subject.) subjects. (Round up to the nearest subject.) A 99% confidence level requires A 95% confidence level requires How does the decrease in confidence affect the sample size required? O A. Decreasing the confidence level increases the sample size needed. B. The sample size is the same for all levels of confidence. OC. Decreasing the confidence level decreases the sample size needed. ...