The results of a recent poll on the preference of shoppers regarding two products are shown below. The standard error of - is
A) .025.
B) .044.
C) .0225.
D) .68.

Question

The results of a recent poll on the preference of shoppers regarding two products are shown below.  ​ The standard error of  -  is
A) .025. 
B) .044. 
C) .0225. 
D) .68.

Quizplus · Accepted Answer

The standard error of the difference between two proportions can be found using the formula SE = sqrt(p1q1/n1 + p2q2/n2), where p1 and p2 are the sample proportions, q1 and q2 are 1-p1 and 1-p2 respectively, and n1 and n2 are the sample sizes. Plugging in the values from the table, we get:
SE = sqrt(0.52*0.48/400 + 0.43*0.57/500) = 0.0225
Therefore, the correct answer is C.

The Results of a Recent Poll on the Preference of Shoppers