In an election campaign, the party vying for an upset polls a sample of 100 voters. The party finds that 60 of 100 clearly express the intention of voting in favour of the party polling. How many voters should be sampled if the party wants to estimate the population proportion with a samplingerror of 5% or less? (Use confidence level of 95%)
p= 60% =60/100= Those in favour of the party, assumed to be the population proportion
q=1-p= 40% = 1 – 0.6= Those not in favour of the party
sample proportion-population proportion(p)= 5% (since sampling error is to be less than 5 %)
Sample size for estimating population proportion is calculated.