Question

mean of 10 no. is 55 .If one no. is excluded their mean becomes 50 .Find the excluded number?

Answer 1

Hey there!

sum of observation\no . of observation=mean
sum of observation= 550
sum of observation-50\9=x
x=500/9
x=55.5555

Hope it help

Answer 2

              sum of the numbers
Mean = -----------------------------
                total numbers

55 = sum/10

sum = 550.

let the number excluded be 'p'

now, new sum = 550 - p

                       new sum         550 - p
new mean = ----------------  =  ------------
                             9                   9

50 = (550 - p)/9

p = 550 - 450 = 100 is the excluded number