The Table given below shows the number of students having obtained different marks.
| Marks | Number of students |
| 9-11 | 6 |
| 11-13 | 5 |
| 13-15 | 2 |
| 15-17 | 2 |
| 17-19 | 5 |
What is the mean marks per student?
Answer & explanation
Correct answer: option 1
Total number of students = 6 + 5 + 2 + 2 + 5 = 20
Mean marks = \(\frac{10 ×6+12 ×5+14 ×2+16 ×2+18 ×5}{20}\)
= \(\frac{60 + 60 + 28 + 32 + 90 }{20}\)
= = \(\frac{270}{20}\)
= 13.5