Question

If mean of x, x+3, x+5, x+7, x+10 is 9, what is mean of last 3 observations?



1)39/4

2)39/3

3)34/3​

Answer 1

Answer:

hey its option 3,when you try to cal mean of the given term u get value of x as 4,he asked mean of last 3 terms so put value of x in them and use mean formula u will get 9,11,14 as last three observation so the mean when you will calculate will be 34/3

Answer 2

Mean= (x+x+3+ x+5+ x+7+ x+10) /5

9×5 = 5x +25

45= 5x+25

20= 5x

4= x

Last three mean are 9,11,14

mean = (9+11+14)/3

mean= 34/3