1. **Problem Statement:** We are given a frequency distribution with class intervals and frequencies. We need to: a) Compute the frequency density for each class. b) Draw a histogram with frequency density on the y-axis. c) Estimate how many data points lie below 18. 2. **Formula for Frequency Density:** Frequency density = \frac{Frequency}{Class width} 3. **Calculate Class Widths:** - For 0–8: width = 8 - 0 = 8 - For 8–20: width = 20 - 8 = 12 - For 20–30: width = 30 - 20 = 10 - For 30–50: width = 50 - 30 = 20 4. **Calculate Frequency Densities:** - 0–8: \frac{12}{8} = 1.5 - 8–20: \frac{24}{12} = 2 - 20–30: \frac{15}{10} = 1.5 - 30–50: \frac{19}{20} = 0.95 5. **Histogram:** The histogram will have class intervals on the x-axis and frequency density on the y-axis with bars of heights 1.5, 2, 1.5, and 0.95 respectively. 6. **Estimate Data Points Below 18:** - The class 0–8 is fully below 18, so all 12 points count. - For 8–20, only the portion from 8 to 18 counts. The width of this portion is 10. - Frequency density for 8–20 is 2, so estimated frequency in 8–18 is 2 \times 10 = 20. - Total estimated data points below 18 = 12 + 20 = 32. **Final answers:** - Frequency densities: 1.5, 2, 1.5, 0.95 - Estimated data points below 18: 32