Question

the mean of ten numbers is 28.if the one number is excluded,their mean is 25. find the excluded number.

Answer 1

Given :-

Mean of ten number = 28

one number is excluded,their mean is 25

To Find :-

Excluded number

Solution :-

We know that

Mean = Sum of observation/Total no. of observation

28 = Sum/10

28 × 10 = Sum

280 = Sum

When one number excluded. Then, no. of observation = 10 - 1 = 9

25 = Sum/9

25 × 9 = Sum

225 = Sum

Now

Excluded number = Sum 1 - Sum 2

Excluded number = 280 - 225

Excluded number = 55

Answer 2

Step-by-step explanation:

• given

meaning of ten number is = 28

one number is excluded , their mean is 25

solution

we know

mean = sum of observation /total no of observation

28 = sum/10

28×10 = sum

280 = sum

one number is excluded .then no of observation = 10-1= 9

25 = sum / 9

25×9 = sum

225 = sum

excluded number = Sum 1 - sum 2

excluded number = 280-225

excluded number = 55

ans is 55 .