At one vehicle inspection station, 13 of 52 trucks and 11 of 88 cars failed the emissions test.
Assuming these vehicles were representative of the cars and trucks in that area, what is the
Standard error of the difference in the percentages of all cars and trucks that are not in compliance
With air quality regulations?
A) 0.070
B) 0.032
C) 0.095
D) 0.049
E) 0.025

Question

Quizplus · Accepted Answer

The standard error of the difference in the percentages of all cars and trucks that are not in compliance with air quality regulations is 0.070. This is calculated by taking the square root of the sum of the variances of the two proportions, which are 0.003 and 0.001, respectively.

At One Vehicle Inspection Station, 13 of 52 Trucks and 11