Question

The mean of the seven numbers is 12. Four of the 7 no.are 10,14,15 and 17. The remaining three numbers are in the ratio 1;2;4 , Find these ratio.​

Answer 1

Answer:

4,8,16

Step-by-step explanation:

mean of 7 no. = 12

sum of 7 no.= 7×12=84

sum of 10+14+15+17=56

sum of remaining 3 no. =84-56=28

let the three no. will be X,2x,4x

A.t.q

X+2x+4x = 28

or,7x= 28

or,X= 4

X=4

2x =2×4=8

4x=4×4=16

last three numbers 4,8,16

Answer 2

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°°° Solution °°°

Given that

Mean of 3 numbers =10.

⇒10= 3

Sum of 3 observations

⇒ Sum of 3 observation =30...(1)

Also given that

Means of other4 numbers =12

⇒12= 4

Sum of 4 observations

⇒ Sum of 4 observation =48...(2)

From equation (1) and (2), we get

Sum of 7 observation =30+48=78

∴ Mean = 778 = 11.14