Question

If the mean of 4,7,x,y and 10 is 8, then find the value of x+y

Answer 1

Solution :

Given mean of 4,7,x,y and 10 is 8

Sum of the observations

= 4+7+x+y+10

= 21 + x + y -----( 1 )

Number of observations

= 5 ----( 2 )

Now ,

mean = 8 ( given )

=> (1)/(2) = 8

=>( 21+x+y)/5 = 8

=> 21+x+y = 40

=> x + y = 40 - 21 = 19

Therefore ,

x + y = 19

••••

Answer 2

No. Of terms = 5

Mean = sum of all terms ÷ no.of terms

Mean=8

So, sum of all terms ÷ no.of terms = 8

4+7+x+y+10÷5 =8

21+x+y÷5=8

On cross multiply,

21+x+y=40

Therefore, x+y=40-21

x+y= 19

Thank you I hope that this answer helps you