Question

. If the arithmetic mean of X , X+3 , X+6 , X+9 and X+12 is 10, then find the value of X

Answer 1

Answer:

Step-1:- X+X+3+X+6+X+9+X+12 =10

5

In first step we have five observations

According to arithmetic mean of ungrouped data,

Sum of observations

No. of observations =mean

Step-2:- Solve the equation of step 1

5X+30 = 10×5

This is fine by cross multiplication and addition

Step-3:-

5X+30 = 50

=> 5X = 50-30

=> 5X = 20

=> X = 20

5

=> X = 4 Answer