JEE Mains · Maths · STD 11 - 13. statistics
The mean and variance of 10 observations are 9 and 34.2, respectively. If 8 of these observations are 2, 3, 5, 10, 11, 13, 15, 21, then the mean deviation about the median of all the 10 observations is
- A 5
- B 4
- C 6
- D 7
Answer & Solution
Correct Answer
(A) 5
Step-by-step Solution
Detailed explanation
\(\frac{2+3+5+10+11+13+15+21+a+b}{10}=9\) \(\frac{80+a+b}{10}=9\) \(\Rightarrow a+b=10\) ..... (1) \(\frac{\Sigma x_{i}^{2}}{10}-(\frac{\Sigma x_{i}}{10})^{2}=34.2\) \(\frac{2^{2}+3^{2}+5^{2}+10^{2}+11^{2}+13^{2}+15^{2}+21^{2}+a^{2}+b^{2}}{10}-(9)^{2}=34.2\)…
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