1. **State the problem:** Calculate the mean, median, mode, and range for the data set: 10, 13, 11, 16, 21, 19, 15, 10, 16, 18, 19, 13, 13, 17, 17. 2. **Mean:** The mean is the average of all numbers. Formula: $$\text{Mean} = \frac{\text{Sum of all data points}}{\text{Number of data points}}$$ Calculate sum: $$10 + 13 + 11 + 16 + 21 + 19 + 15 + 10 + 16 + 18 + 19 + 13 + 13 + 17 + 17 = 244$$ Number of data points: 15 Calculate mean: $$\frac{244}{15} = 16.27$$ (rounded to two decimals) 3. **Median:** The median is the middle value when data is ordered. Order data: 10, 10, 11, 13, 13, 13, 15, 16, 16, 17, 17, 18, 19, 19, 21 Since 15 data points, median is the 8th value: 16 4. **Mode:** The mode is the most frequent value(s). Count frequencies: 10(2), 11(1), 13(3), 15(1), 16(2), 17(2), 18(1), 19(2), 21(1) Mode is 13 because it appears 3 times. 5. **Range:** The range is the difference between the maximum and minimum values. Max = 21, Min = 10 Range = $$21 - 10 = 11$$ **Final answers:** - Mean = 16.27 - Median = 16 - Mode = 13 - Range = 11