Question

The height of 10 students, measured in cm are as follows:
143, 132, x, 139, 128, 135, 151, 146, 141, 149.
If mean of the given information is 141.4 cm, then find the value of x.

• A. 150 cm
• B. 141 cm
• C. 142 cm
• D. 151 cm

Answer 1

The correct option is A 150 cm

$\text{Mean height}=\frac{\text{Sum of all the heights}}{\text{No. of students}}$
i.e., $141.4=\frac{143+132+x+139+128+135+151+146+141+149}{10}$

$\Rightarrow 141.4=\frac{1264+x}{10}$

$\Rightarrow 1264+x=141.4\times 10$

$\Rightarrow 1264+x=1414$

$\Rightarrow x=1414-1264=150\text{cm}$

Therefore, the value of x is 150 cm.