n= N/ 1+N (e) 2
Remark: n= Sample Size, N= Number of
population, e= Significance level
According to Yamane’s formula, when the
level of precision is specified to be 5% and
however, the bias result could be happened
if the number of sample is relatively small
compared to the number of population as
whole. This problem could be limited by
increasing the number of sample.