Let
m1,
r1 and
v1 be the mean, the range and the variance of a group of numbers
{x1,x2,x3,…,x100} respectively. If
m2,
r2 and
v2 are the mean, the range and the variance of the group of numbers
{x1,x2,x3,…,x100,m1} respectively, which of the following must be true?
I.
m1=m2II.
r1=r2III.
v1=v2