From a lot of 10 items, which include 3 defective items, a sample of 5 items is drawn at random. Let the random variable X...

Let a,b∈R. Let the mean and the variance of 6 observations -3,4,7,-6,a,b be 2 and 23 , respectively. The mean deviation about the mean of...

The mean and standard deviation of 20 observations are found to be 10 and 2, respectively. On respectively, it was found that an observation by...

If the mean and variance of the data 65,68,58,44, 48, 45, 60, α,β,60 where α>β are 56 and 66.2 respectively, then $\alpha^2+\beta^2$ is equal to

Let M denote the median of the following frequency distribution. Then 20 M is equal to :

Let the median and the mean deviation about the median of 7 observation 170, 125, 230, 190, 210, a, b be 170 and 205/7 respectively....

Let $a_1, a_2, \ldots . . a_{10}$ be 10 observations such that $\sum_{\mathrm{k}=1}^{10} \mathrm{a}_{\mathrm{k}}=50$ and $\sum_{\forall \mathrm{k}<\mathrm{j}} \mathrm{a}_{\mathrm{k}} \cdot \mathrm{a}_{\mathrm{j}}=1100$. Then the standard deviation of...

The mean and standard deviation of 100 observations are 40 and 5.1, respectively. By mistake one observation is taken as 50 instead of 40. If...