If the arithmetic mean of the numbers x1,x2,x3,…,xn is x¯ , then the arithmetic mean of the numbers ax1+b,ax2+b , ax3+b,…,axn+b, where a,b are two constants, would be
x
nax+nb
ax
ax+b
Required Mean
=ax1+b+ax2+b+⋯+axn+bn=ax1+x2+⋯+xnn+b=ax¯+b∵x1+x2+⋯+xnn=x¯