1. **State the problem:** We are given I.Q. scores of 60 children and need to form a frequency distribution with class intervals of width 15. Then, we will locate the mode graphically. 2. **Determine the range:** Find minimum and maximum values. - Minimum = 43 - Maximum = 153 3. **Find the class intervals:** Start at 40 (just below 43), width = 15. Classes: - 40 - 54 - 55 - 69 - 70 - 84 - 85 - 99 - 100 - 114 - 115 - 129 - 130 - 144 - 145 - 159 4. **Tally frequencies:** - 40-54: 43,54 → 2 - 55-69: 67 → 1 - 70-84: 72,73,76,76,79,79,80,81,84,84 → 10 - 85-99: 85,87,88,89,89,90,93,94,94,94,95,96,96,97,97,98,98,99 → 18 - 100-114: 100,101,101,102,102,102,103,103,105,107,109,109,110,110,111,112,114,115 → 18 - 115-129: 115,118,119,120,122,123,127,128 → 8 - 130-144: 132 → 1 - 145-159: 146,153 → 2 5. **Frequency distribution table:** | Class Interval | Frequency | | 40 - 54 | 2 | | 55 - 69 | 1 | | 70 - 84 | 10 | | 85 - 99 | 18 | | 100 - 114 | 18 | | 115 - 129 | 8 | | 130 - 144 | 1 | | 145 - 159 | 2 | 6. **Locate the mode graphically:** - Plot a histogram using midpoints of each class vs. their frequency. - The modal class is the one with the highest frequency. - Here, classes 85-99 and 100-114 both have the highest frequency 18. 7. **Modal class:** Since two classes share the highest frequency, the distribution is bimodal with modes in 85-99 and 100-114.