Use the following information to answer question 9: Of 1,050 randomly selected adults, 360 identified themselves as manual laborers, 280 identified themselves as non-manual wage earners, 250 identified themselves as mid-level managers, and 160 identified themselves as executives. In the survey, 82% of manual laborers preferred trucks, 62% of non-manual wage earners preferred trucks, 54% of mid-level managers preferred trucks, and 26% of executives preferred trucks.

9. We are specifically interested in the percent of executives who prefer trucks. Construct a 95% confidence interval. State the confidence interval, sketch the graph, and calculate the error bound. (3 points)