1.Construct a confidence interval for p1p2 at the given level of confidence.

x1=391, n1=536, x2=419, n2=565, 95% confidence

The researchers 95% confident the difference between the two populationproportions, p1p2, is between _____and ____

(Use ascending order. Integer or decimal rounded to three decimal places asneeded.)

2.A doctor wants to estimate the mean HDL cholesterol of all20- to29-year-old females. How many subjects are needed to estimate the mean HDL cholesterol within 2 points with 99% confidence assuming s=11.6 based on earlierstudies? Suppose the doctor would be content with 90% confidence. How does the decrease in confidence affect the sample sizerequired?

required? 100. i Partial Critical Value Table - X le size needed, blo size needed Level of Confidence, Area In Each Tall, Critical Value, Z /2 (1 -() . 100% 2 90% 0.05 1.645 95% 0.025 1.96 0.005 2.575 Print Done