The popularity of online auction websites has risen dramatically as many shoppers choose to shop online instead of at retail stores. The data provided describe the sale prices of the video game Mario Kart Wii on one such online auction site during the month of October in 2009.The variables included in this data set are: the duration of the auction in days, the number of bids placed on the Mario Kart game, whether or not the auction's picture used a stock photo, the starting price of the game in dollars, the final price of the game in dollars, the condition of the game, and whether or not the game was packaged with toy steering wheels used during gameplay. Determine which of these variables (in bold) in the data set are indicator variables.