Question

the mean of five observations is 10. if one observation is deleted the mean of the remaining four observations is 11. the deleted observation is​

Answer 1

Given:

The mean of five observations is 10

To find:

The deleted observation

Solution:

The mean of the observation given by the ratio of the sum of the observation to the number of the observations

So the sum of the observation when the mean is 10 and the number of the observation is 5

Old Sum = 10*5

Old sum = 50

So the sum of the observation when the mean is 11 and the number of the observation is 4

• New Sum = 11*4
• New sum = 44

The deleted observation is given by:

• Term = Old Sum - New Sum
• Term = 50-44
• Term = 6

So the deleted term is 6