Question

Find the average height of students in a class from the given table:

$\begin{array}{cc}\text{Height in cm}& \text{Number of students}\\ 120& 5\\ 130& 6\\ 140& 9\\ 150& 10\\ 160& 4\\ 170& 2\end{array}$

• A. 150
• B. 140
• C. 142.22
• D. 152.22

Answer 1

The correct option is C

142.22

The frequency (f) in the given data will be number of students.

Here, the total number of students is 36.

Now, the average height of students = $\frac{(120\times 5)+(130\times 6)+(140\times 9)+(150\times 10)+(160\times 4)+(170\times 2)}{5+6+9+10+4+2}$

= $\frac{600+780+1260+1500+640+340}{36}$

= $\frac{5120}{36}$

= 142.22

So, the average height of students is 142.22 cm.