This procedure provides a basic method of calculating the statistical power of a test given a certain number of cases. Basically what the program does is to give you the probability of finding the difference between average one and average two statistically significant. This given a certain sample size and standard deviation. Standard deviations are not required if the averages are proportions, decimal numbers between 'zero' and 'one'. The procedures implemented here are only applicable for simple random samples and to compare two averages.
Input is made as simple as possible.
The program recognizes a proportion by there being a number between 'zero' and 'one' in the first box and a standard deviation of 'zero' in the third box, in which case the program expects to also find a proportion in the second box. A specific proportion related method will be used to estimate the statistical power. In the case of a value of 'one' or more in the first box a method will be used which considers that the values given are averages. The program obtains the standard deviation of each of the two averages by taking the square root of the average. If one or two standard deviations are given, the program will treat the given averages always as an average, even if one or both are between 'zero' and 'one'.