The mean of 5 observations is 50. One of the observation was removed from the data, hence the mean became45. Find the observation which was removed

If the mean of 10 observations is 12, what is their sum?

The mean of 35 observations is 20. If the mean of the first 18 observations is 16 and that of last 18 observations is 24, find the 18th observation.

The mean of the following observations is 20.2. Find the value of p.

mean of 100 observations is 40. The 9 observation is 30. If this is replaced by 70 keeping all other observation same, find the new mean.

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