Cohen's d is calculated as the difference between two means divided by the pooled standard deviation. The formula is:
d = (M1 - M2) / SDpooled
Where M1 and M2 are the means of the two groups, and SDpooled is the pooled standard deviation. The pooled standard deviation is calculated using the formula:
SDpooled = √((SD1² + SD2²) / 2)
Here, SD1 and SD2 are the standard deviations of the two groups.
