Formula Of Sample Size Calculation. A 95 confidence level andP5are assumed for Equation 5. Where z 1645 for a confidence level α of 90 p proportion expressed as a decimal e margin of error.
Jun 02 2015 Example. N Population size Z Critical value of the normal distribution at the required confidence level p Sample proportion e Margin of error. 196 for 95 confidence level p percentage picking a choice expressed as decimal.
Z 2 p 1-p c 2.
The Taro Yamane method for sample size calculation was formulated by the statistician Tara Yamane in 1967 to determine the sample size from a given population. N population size e Margin of error percentage in decimal form z z-score The z-score is the number of standard deviations a given. This equation is for an unknown population size or a very large population size. If we are using three independent variables then a clear rule would be to have a minimum sample size of 30.
