Mean = ∑x/n --> n(mean) = ∑x
(68*20) + (75*25) + (60*32) = ?
Divide that by 20 + 25 + 32 = ?
Average SD Number of Students
Section 1 68 9 20
Section 2 75 9 25
Section 3 60 9 32
Find the average score of all the students in the class.
(68*20) + (75*25) + (60*32) = ?
Divide that by 20 + 25 + 32 = ?
The weighted average formula is:
Average = (Sum of (Average * Number of Students)) / Total Number of Students
Let's calculate it step by step:
1. Calculate the sum of (Average * Number of Students) for each section:
Section 1: (68 * 20) = 1360
Section 2: (75 * 25) = 1875
Section 3: (60 * 32) = 1920
2. Calculate the total number of students:
Total Number of Students = 20 + 25 + 32 = 77
3. Calculate the weighted average by dividing the sum of (Average * Number of Students) by the total number of students:
Weighted Average = (1360 + 1875 + 1920) / 77
4. Calculate the final answer:
Weighted Average = 5155 / 77 ≈ 66.95
Therefore, the average score of all the students in the class is approximately 66.95.