90 percent confidence interval for the proportion difference p1-p2 was calculated to be (0.247,0.325). Which of the following conclusions is supported by the interval?

A. There is evidence to conclude that p1>p2 because 0.325 is greater than 0.247.

B. There is evidence to conclude that p1 C. There is evidence to conclude that p1>p2 because all values in the interval are positive.

D. There is evidence to conclude that p1 E. There is evidence to conclude that p2>p1 because 0.247 and 0.325 are both greater than 0.05.

Question

Mathematics

Jovanny Figueroa

16 January, 19:25

90 percent confidence interval for the proportion difference p1-p2 was calculated to be (0.247,0.325). Which of the following conclusions is supported by the interval?

A. There is evidence to conclude that p1>p2 because 0.325 is greater than 0.247.

B. There is evidence to conclude that p1 C. There is evidence to conclude that p1>p2 because all values in the interval are positive.

D. There is evidence to conclude that p1 E. There is evidence to conclude that p2>p1 because 0.247 and 0.325 are both greater than 0.05.

+4

Answers (1)

Know the Answer?

Jayson Clements · Answer 1

C

Step-by-step explanation:

Statistics!

When we have a confidence interval for the difference in proportions or means, our null hypothesis is always that there's no difference. (H0 = p1-p2 = 0.)

If the difference is positive, that means we have sufficient evidence p1>p2.

If it's negative, then we have sufficient evidence p2>p1.

Why not A: incorrect interpretation of the interval

Why not B: doesn't look like a complete answer

Why not D: also doesn't look like a complete answer

Why not E: this confuses the definition of alpha-level and p-value with confidence interval values. If those were p-values and greater or less than an alpha-level, we would reject or fail to reject the null hypothesis. That isn't the case here.