If the sample proportions were p₁ = 12/50 and p₂ = 18/50, the 95 percent confidence interval for the difference of the population proportions is approximately: A)[-.144, +.244]. B)[-.120, +.120]. C)[-.298, +.058]. D)[-.011, +.214].

Question

Quizplus · Accepted Answer

To find the confidence interval for the difference in population proportions, we can use the formula:

CI = (p1 - p2) ± z*sqrt( (p1(1-p1)/n1) + (p2(1-p2)/n2) )

where p1 and p2 are the sample proportions, n1 and n2 are the sample sizes, and z is the standard normal value for the desired level of confidence (in this case, 95%).

Substituting the given values, we get:

CI = (12/50 - 18/50) ± 1.96*sqrt( (12/50)(38/50)/50 + (18/50)(32/50)/50)

CI = (-0.12) ± 0.178

CI = [-0.298, 0.058]

Therefore, the best choice is C.

If the Sample Proportions Were P1 = 12/50 and P2

If the Sample Proportions Were P₁ = 12/50 and P₂