Manual Transmission Automobiles In 1980 more than 35% of cars purchased had a manual transmission (1.e. stick shift). By 2007 the proportion had decreased to 7.7%. A random sample of college students who owned cars revealed the following: out of 133 cars, 31 had stick shifts. Estimate the proportion of college students who drive sticks with 90% confidence. Use a graphing calculator and round the answers to at least three decimal places. 0