A Doctor Wants To Estimate The Mean Hdl Cholesterol Of All 20 To 29 Year Old Females How Many Subjects Are Needed To E 1 (136.04 KiB) Viewed 63 times
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 4 points with 99% confidence assuming s= 17.3 based on earlier studies? Suppose the doctor would be content with 90% confidence. How does the decrease in confidence affect the sample size required? Click the icon to view a partial table of critical values. A 99% confidence level requires subjects. (Round up to the nearest subject.) A 90% confidence level requires subjects. (Round up to the nearest subject.) How does the decrease in confidence affect the sample size required? A. The sample size is the same for all levels of confidence. B. Decreasing the confidence level decreases the sample size needed. C. Decreasing the confidence level increases the sample size needed.
A trade magazine routinely checks the drive-through service times of fast-food restaurants. A 95% confidence interval that results from examining 711 customers in one fast-food chain's drive-through has a lower bound of 167.5 seconds and an upper bound of 171.3 seconds. What does this mean? Choose the correct answer below. O A. One can be % confident that the mean drive-through service time of this fast-food chain is between seconds and seconds. B. There is a seconds and seconds. % probability that the mean drive-through service time of this fast-food chain is between OC. The mean drive-through service time of this fast-food chain is seconds % of the time. D. One can be O % confident that the mean drive-through service time of this fast-food chain is seconds.
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