Question

Consider a simple random sample (WOR) of three household from a population of 5 house hold having monthly income (in $) as follows:
Household 1 2 3 4 5
Income(in $) 1500 1450 1600 1650 1550
Enumerate all the possible samples in SRS WOR of size 3 and show that the sample mean givens an unbiased estimate of population mean.