Question

the arithmetic mean of x,y and z is 6 while that of x,y,z,t,u,v and w is 9. Calculate the erithmetic mean of t, u, v and w

Answer 1

mean = ∑x/n

6 = (x+y+z)/3

9 = (x+y+z+t+u+v+w)/7

63 = (x+y+z+t+u+v+w)

18 = (x+y+z)

mean = (63-18)/4 = ?

Answer 2

mean = ∑x/n
6 = (x+y+z)/3
9 = (x+y+z+t+u+v+w)/7
63 = (x+y+z+t+u+v+w)
18 = (x+y+z)
mean = (63-18)/4 =