What is the variance of the largest five observation?

The mean of 5 observations is 4 and their variance is 5.2. If three of those observations are 1, 2 and 6, the other two are:

If 25% of items are less than 20 and 25% are more than 40, the quartile deviation is:

The mean and standard deviation of a Binomal distribution are 4 and $$\sqrt{\frac83}$$ respectively. With usual notations, values of n and p are​

The mean of 5 observations is 4 and their variance is 5.2. If three of those observations are 1, 2 and 6, the other two are:

If 25% of items are less than 20 and 25% are more than 40, the quartile deviation is: