{"id":6980,"date":"2021-10-22T02:28:51","date_gmt":"2021-10-21T20:58:51","guid":{"rendered":"https:\/\/mathemerize.com\/?p=6980"},"modified":"2021-10-25T09:30:26","modified_gmt":"2021-10-25T04:00:26","slug":"find-the-variance-of-first-n-even-natural-numbers","status":"publish","type":"post","link":"https:\/\/mathemerize.com\/find-the-variance-of-first-n-even-natural-numbers\/","title":{"rendered":"Find the variance of first n even natural numbers ?"},"content":{"rendered":"
\\(\\therefore\\) Variance = [\\({1\\over n}\\sum{(x_i)^2}\\)] – \\((\\bar{x})^2\\)<\/p>\n
= \\(1\\over n\\)[\\(2^2 + 4^2 + ….. + (2n)^2\\)] – \\((n+1)^2\\)<\/p>\n
= \\(1\\over n\\)\\(2^2 [ 1^2 + 2^2 + ….. + n^2]\\) – \\((n+1)^2\\)<\/p>\n
= \\(4\\over n\\) \\(n(n + 1)(2n + 1)\\over 6\\) – \\((n+1)^2\\)<\/p>\n
= \u00a0\\((n + 1)[(2n + 1) – 3(n + 1)\\over 3\\)<\/p>\n
= \\((n + 1)(n – 1)\\over 3\\) = \\(n^2 – 1\\over 3\\)<\/p>\n
The mean and variance of a random variable X having a binomial distribution are 4 and 2 respectively, then P(X = 1) is<\/a><\/p>\n The mean and variance of 5 observations of an experiment are 4 and 5.2 respectively. If from these observations three are 1, 2 and 6, then remaining will be<\/a><\/p>\n The mean and the variance of a binomial distribution are 4 and 2, respectively. Then, the probability of 2 success is<\/a><\/p>\n In a series of 2n observations, half of them equals a and remaining half equal -a. If the standard deviation of the observation is 2, then |a| equal to<\/a><\/p>\n