TABLE 10-11
A corporation randomly selects 150 salespeople and finds that 66% who have never taken a self-improvement course would like such a course. The firm did a similar study 10 years ago in which 60% of a random sample of 160 salespeople wanted a self-improvement course. The groups are assumed to be independent random samples. Let ×and × represent the true proportion of workers who would like to attend a self-improvement course in the recent study and the past study, respectively.
-Referring to Table 10-11, what is the estimated standard error of the difference between the two sample proportions?
A) 0.055
B) 0
C) 0.500
D) 0.629

Question

Quizplus · Accepted Answer

The estimated standard error of the difference between two sample proportions is calculated using the formula: SE = sqrt[(p1(1-p1)/n1) + (p2(1-p2)/n2)], where p1 and p2 are the sample proportions, and n1 and n2 are the sample sizes. Plugging in the values: SE = sqrt[(0.66(1-0.66)/150) + (0.60(1-0.60)/160)] ≈ 0.055.

TABLE 10-11 A Corporation Randomly Selects 150 Salespeople and Finds That 66