Question

the mean of six number is 23.if one of the number is excluded, the mean of the remaining number is 20. find the excluded number.

Answer 1

Answer:

Step-by-step explanation:

Let the sum of all observation be x.

Mean = Sum of all observation/

Total number of observation

Old mean:

=> 23 = x/6

=> x = 23*6 = 138

If one number is excluded mean becomes 20.

So, total no. of observation = 6-1 = 5

New mean:

=> 20 = x/5

=> x = 20*5

=> x = 100

No. excluded = Old mean - New mean

=> 138 - 100

=> 38

So, the excluded no. is 38.

Answer 2

ANSWER........................,

The mean of 6 number = 23

The sum of 6 number = 6 × 23 = 138

If one number is excluded ,

Then mean of 5 number = 20

Sum of 5 number = 5 × 20 = 100

∴excluded number = 138 - 100 = 38