Good Sample Size For Survey. Mar 15 2004 That is a sample of 250 will give you a 6 percent margin of error and a sample size of 100 will give you a 10 percent margin of error. This means that a sample of 500 people is equally useful in examining the opinions of a state of 15000000 as it would a city of 100000.
For example in a population of 5000 10 would be 500. You can use the responses to help you determine how your audience will react to the new product. Jul 15 2010 For example if youre asking respondents to rate how satisfied they are with a service on a 7-point scale and want no more than a 5 margin of error then youll need to plan on obtaining 249 responses.
N z 2 p 1 - p e 2.
Calculate sample size Now that youve got answers for steps 1 4 youre ready to calculate the sample size you need. A good bet for standard deviation is 5 but you can use this free standard deviation calculator if you want to get more accurate. Mar 15 2004 That is a sample of 250 will give you a 6 percent margin of error and a sample size of 100 will give you a 10 percent margin of error. For education surveys we recommend getting a statistically significant sample size that represents the population.
