A company is interested in the effectiveness of radio advertising and newspaper advertising (including the cost of discount coupons). During a one-month test period, data were collected from a sample of 22 cities with approximately equal populations. Each city is allocated a specific expenditure level for radio advertising and for newspaper advertising. The sales of the product (in thousands of dollars) and also the levels of media expenditure (in thousands of dollars) during the test month are recorded. A regression tree model was developed to predict the sales of the product using all the data as a training sample. What conclusions can you reach about the sales of the product? Click the icon to view the sample data. 1 Click the icon to view the regression tree model. The sales were higher for cities where Among those cities, the sales were higher where the thousand dollars. sample data advertising was thousand dollars. advertising was - Full data set Sales Radio Newspaper Sales Radio Newspaper 1187 0 24 1469 27 27 1219 0 24 1217 30 0 840 15 15 1127 30 0 703 15 15 1236 33 15 1017 18 18 1360 33 15 1164 18 18 1383 36 18 1153 21 21 1403 36 18 1230 21 21 1469 39 21 858 24 15 1672 39 21 1194 24 15 1723 42 24 Check answer 1581 27 27 1625 42 24 classification tree model Number RSquare 0.708 RMSE N of Splits 141.77618 22 2 All Rows Count 22 Mean 1265.00 Std Dev 268.4272 LogWorth 5.117313 Difference 382.25 Radio > 27 Count 12 Mean 1438.75 Std Dev 188.2972 LogWorth 5.750260 Difference 302.17 Newspaper 21 Count Newspaper <21 190.3536