Q269 / 270 · NDA 2024 (Phase 1) · Mathematics
The marks obtained by 10 students in a Statistics test are $24,47,18,32,19,15,21,35,50$ and 41.
What is the mean deviation of the largest five observations?
- A4.8
- B5.5
- Correct answerC6
- D7.5
Solution
$\because 15,18,19,21,24,32,35,41,47,50$
Largest 5 observations are $32,35,41,47,50$
$\begin{aligned}
\text { Mean } & =\mu=\frac{32+35+41+47+50}{5} \\
& =\frac{205}{5}=41
\end{aligned}$
Mean deviation $=\frac{\Sigma\left|x_i-\mu\right|}{n}$
$\begin{aligned} & =\frac{|32-41|+|35-41|+|41-41|+|47-41|+|50-41|}{5} \\ & =\frac{9+6+0+6+9}{5}=\frac{30}{5}=6\end{aligned}$
Hence, the correct answer is option: 'C'.