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Exercise

What did people choose?

Before we fit a model, we want to get a sense for what people choose as a function of each product attribute. The best way to do this is to count how many times a car with a particular feature is chosen. In this exercise, we are going to focus on the transmission feature and count up the number of times chosen cars have manual transmissions versus automatic using the xtabs() function.

Instructions
100 XP
  • Change the formula in the xtabs() function to choice ~ trans, which means "sum up the choice variable for each level of the trans variable."
  • Print the chosen_by_trans table to the console by typing its name. How many times were cars with manual transmissions chosen versus automatic?
  • Plot the chosen_by_trans object using the barplot() function.