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Feb
Confidence Interval Calculator Sample Size. This equation is for an unknown population size or a very large population size. The margin of error portion of a confidence interval formula can also be used to estimate the sample size that needed. Calculates the sample size to achieve the required confidence interval. The calculation is based on the following binomial equation.
Example What sample size should you use for a survey in a city with a population of 120000 people. The Sample Size Calculator uses the following formulas. To calculate it for each confidence level you can use the following formula. The confidence interval is the plus-or-minus figure usually reported in newspaper or television opinion poll results. Just click on QI Macros menu then Calculators then Sample Size Calculator. Confidence interval m -.
If left blank it will be assumed to be 05.
This calculator gives both binomial and normal approximation to the proportion. Enter parameters in the green cells. Estimate the mean value of a continuous measurement using a single sample. Press Calculate to perform the calculation or Clear to start again. Confidence Interval Confidence Level. For example if you use a confidence interval of 4 and 47 percent of your sample picks an answer you can be sure that if you had asked the question of the entire relevant population between 43 47-4 and 51.