Statistics for everyone: ch.29 mean of two groups

easier R than SPSS with Rcmdr : Contents

ch.29 mean of two groups

Select the Sample size menu. The submenu will be expanded as shown below.

The second common thing is a study that compares means.

Enter the expected mean difference and standard deviation in the two populations.

It shows that a sample of 56 people is needed for each group.

It also shows a similar graph, and the interpretation is the same. In the future, we will omit plot except in special cases.

If your time and economic budget allows, you will want to increase the power as much as possible, in which case you can estimate how much power you can increase by increasing the number of N in this graph. As the number of N increases, it is possible that cost and time will increase proportionally, but power is gradually becoming a horizon, so you might want to consider an appropriate compromise by looking at the relationship between the two.

easier R than SPSS with Rcmdr : Contents

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