Out of 30 observations , 10 observations are `(1/2-d)` and 10 observations are d and remaining 10 are `(1/2+d)`. If the variance of 30 observation is `4/3` then d is `

In a series of 20 observations 10 observation each equal to k and each of the remaining half is equal to -k .If the standard deviation of the observations is 2, then write the value of k

Mean of 5observations is 7. If four of these observations are 6,7,8,10 and one is missing then the variance of all the five observations is

The mean and variance of the 7 observations is 8 and 12 resp. . If two observations are 8 and 6 . find the variance of the remaining observation

The mean and variance of 7 observations are 8 and 16 respectively. If two observations are 6 and 8, then the variance of the remaining 5 observations is :

Mean of 5 observation is 7. if four of these observation are 6,7,8,10 and one is missing, then te variance of all the five observations is

If the sum and sum of squares of 10 observations are 12 and 18 resp.then,The S.D.of observations is :-

The variance of 15 observations is 4. If each observations increased by 9 find the variance of the resulting observations.

Given the variance of 30 observations is 20. if each of the observations is divided by 2, then new variance of the resulting oservations is