13. The National Institutes of Health funded a study of a randomsample of 856 people age 71 and older in the United States. Theyfound that 9.7% of these people suffer from Alzheimer’sDisease.
a.Is .097 (the decimal version of 9.7%) a parameter or astatistic? What symbol do you use to represent 0.097?
b.
First, calculate the lower end of the confidence interval.
Report your answer to three decimals and round appropriately;e.g., 0.xxx (3 points)
c.
Next, calculate the upper end of the interval.
Report your answer to three decimals and round appropriately;e.g., 0.xxx. (1 point)
d. If you were to calculate a 90% confidence interval, would itbe wider or narrower than the 95% confidence interval? (1point)
