Estimate The Minimum Sample Size Needed To Achieve The Margin Of Error. Each time you survey one more person the cost of your survey increases and going from a sample size of say 1500 to a sample size of 2000 decreases your margin of error by only 034 one third of one percent from 00253 to 00219. Using the sample size formula you calculate the sample size you need is which you round up to 211 students you always round up when calculating n.
This is the minimum sample size therefore we should round up to 601. MOE is the margin of error z is the z-score associated with a level of confidence p is the sample proportion expressed as a decimal n is the sample size N is the population size. Using a sample size of 5 and 7 would result of a margin of error of approximately 1430 and 1102 respectively.
The extra cost and trouble to get that small decrease in the margin of error may not be worthwhile.
It is expressed as a. Find the approximate margin of error and the 95 confidence interval for the population proportion. A population proportion is to be estimated. Using a sample size of 5 and 7 would result of a margin of error of approximately 1430 and 1102 respectively.
