Question

Q9 mean of 5 numbers is 20. If one number is excluded,
mean of remaining number becomes 23. Find excluded​

Answer 1

Answer:

Mean = sum/no. of observations

20 = sum/5

sum = 20×5 = 100

Sum of 5 numbers is 100

Now one number is excluded. Let the number be x

So the sum becomes 100 - x

No. of observations = 4

Mean = 23

23 = (100 - x) / 4

100 - x = 23×4

100 - x = 92

100 - 92 = x

x = 8

The number which is excluded is 8

Pls follow....

Answer 2

Given,

The mean of 5 numbers = 20

So, the total sum of the numbers = 20 x 5 = 100

After excluding one number,

The mean of the remaining 4 numbers = 23

So, the total sum of these numbers = 23 x 4 = 92

Hence,

The excluded number is = 100 – 92 = 8.