TS EAMCET · Maths · Statistics
The mean and standard deviation of a distribution of weights of a group of 20 boys are \(40 \mathrm{~kg}\) and \(5 \mathrm{~kg}\) respectively. If two boys of weights \(43 \mathrm{~kg}\) and \(37 \mathrm{~kg}\) are excluded from this group, then the variance of the distribution of weights of the remaining group of boys is
- A 26.18
- B 5.27
- C 26.78
- D 5.17
Answer & Solution
Correct Answer
(C) 26.78
Step-by-step Solution
Detailed explanation
Here, \(n=20\) Mean \(=40\) Mean \(=\frac{\text { Sum of observation }}{n}\) \(\Rightarrow 40=\frac{\text { Sum of weights }}{20}\) Sum of weights \(=20 \times 40=800\) Now, standard deviation, \(\sigma=5\) \(\because\) variance \(=\sigma^2=5^2=25\) Now, two boys are excluded of…
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