1. In a survey of 1000 people who attend community college, 15% are age 40 or older. (Adapted from American Association of Community Colleges) (a) Construct a 95% confidence interval for the proportion of people who attend community college that are age 40 or older. (b) A researcher claims that more than 12% of people who attend community college are age 40 or older. At a = 0.05, can you support the researcher's claim? Interpret the decision in the context of the original claim. 2. Gas Mileage The table shows the gas mileages (in miles per gallon) of eight cars with and without using a fuel additive. At a = 0.10, is there enough evidence to conclude that the additive improved gas mileage? Assume the populations are normally distributed. Car N 3 4 Gas mileage (without fuel additive) 23.1 25.4 21.9 24.3 Gas mileage (with fuel additive) 23.6 27.7 23.6 26.8 Car 5 6 7 Gas mileage (without fuel additive) 19.9 21.2 25.9 24.8 Gas mileage (with fuel additive) 22.1 22.4 26.3 26.6