Running `find_test_stat(helicopters, "Rotor", "Time")` should return the exact same value your code from the previous question computed: the difference between of average values in the "Time column between the groups determined by "Rotor" column in the `helicopters` table. However, you should also be able to run `find_test_stat(helicopters, "Weight", "Time")` to computer the difference between of average values in the **"Weight"** column between the groups determined by "Rotor" column in the `helicopters` table just as easily.