Question

the mean of 10 scores is 27. if 1 score is excluded,their mean is 25. Find the excluded number. plz give the full solution​

Answer 1

The sum of 10 numbers = (27*10)

                                        = 270

The some of the other 9 numbers, except the excluded number= (25*9)

                                                                                                           = 225

So, the excluded number is = (270- 225)

                                               = 45

 

Answer 2

Given - Mean of 9 and 10 numbers

Find - Excluded number

Solution - Mean = sum of all scores/total number of scores

Case of 10 scores -

Sum of 10 scores = 27*10

Sum of 10 scores = 270

Case of 9 scores -

Sum of 9 scores = 25*9

Sum of 9 scores = 225

Excluded number = sum of 10 scores - sum of 9 scores

Excluded number = 270 - 225

Excluded number = 45

So, the excluded number is 45.