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Question
The marks obtained by 30 students in a class assignment of 5 marks are given below.
| Marks | 0 | 1 | 2 | 3 | 4 | 5 |
| No. of Students |
1 | 3 | 6 | 10 | 5 | 5 |
Calculate the mean, median and mode of the above distribution
Solution
| Marks (x) | 0 | 1 | 2 | 3 | 4 | 5 | Total |
| No. of Students (f) | 1 | 3 | 6 | 10 | 5 | 5 | n = 30 |
| fx | 0 | 3 | 12 | 30 | 20 | 25 | `sum fx = 90` |
| c.f | 1 | 4 | 10 | 20 | 25 | 30 |
Mean = `(sum fx)/n = 90/30 = 3`
Number of observations 30 (even)
∴ Median = `((n/2)^"th" "observation" + (n/2 + 1)^"th" "observation" )/2`
`= ((30/2)^"th" "observation" + (30/2 + 1)^"th" "observation")/2`
`= (15th "observation" + 16 th "observation")/2`
`= (3 + 3)/2`
= 3
Mode = The number (marks) with highest frequency = 3
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