Question

The mean of 10 number is 55 .If one no. is excluded , their mean becomes 50 , the excluded no. is

Answer 1

Answer:100

Step-by-step explanation:

let the total sum of numbers be x

Mean=total sum/no. of observation =55

So, x/10=55

x=550

Let the number excluded be y

According to question

550-y/9=50

550-y=450

y=100

So the excluded number is 100.

Answer 2

Answer:

Step-by-step explanation:

Let the excluded no: be 'a' and the total after excluding the num be 'b'

i)   Mean = Sum of num/Total no of numbers

    55 = b + a /10

     a+b = 550

ii)  Mean = Sum / Total num of numbers

          50 = b/9

         b = 450

Substituting b = 450 in the found out equation

 a + 450 = 550

 a = 100

so, the excluded no: is 100

Hope for brainliest!!