JEE Main & Advanced Mathematics Statistics Question Bank Self Evaluation Test - Statistics

  • question_answer
    The variance of first 50 even natural numbers is

    A) 437

    B) \[\frac{437}{4}\]

    C) \[\frac{833}{4}\]

    D) \[833\]

    Correct Answer: D

    Solution :

    [d] First 50 even natural numbers are 2, 4, 6?,100 Variance \[=\frac{\sum{x_{i}^{2}}}{N}-{{(\bar{x})}^{2}}\] \[\Rightarrow {{\sigma }^{2}}=\frac{{{2}^{2}}+{{4}^{2}}+...+{{100}^{2}}}{50}-{{\left( \frac{2+4+...+100}{50} \right)}^{2}}\] \[=\frac{4({{1}^{2}}+{{2}^{2}}+{{3}^{2}}+...+{{50}^{2}})}{50}-{{(51)}^{2}}\] \[=4\left( \frac{50\times 51\times 101}{50\times 6} \right)-{{(51)}^{2}}=3434-2601\] \[\Rightarrow {{\sigma }^{2}}=833\]


You need to login to perform this action.
You will be redirected in 3 sec spinner