The following table gives the number of boys of a particular age in a class of 40 students. Calculate the mean age of the students.
Age (in year): | 15 | 16 | 17 | 18 | 19 | 20 |
No. of students: | 3 | 8 | 10 | 10 | 5 | 4 |
Age (x) | No. of students (y) | yx |
15 | 3 | 45 |
16 | 8 | 128 |
17 | 10 | 170 |
18 | 10 | 180 |
19 | 5 | 95 |
20 | 4 | 80 |
N = 40 | ∑yx = 698 |
Mean =
= = 17.45
Therefore, mean age is 17.45 years.