at 08:22 (time in video) in example of calculation of minimum sample size; p = Pooled proportion = (µ1 - µ2)/2 but, actual calculation is (0.33 + 0.33 + 0.02)/2 HOW???????

I am jumping on to this one, too. The code is not compatible with the equation in the video.

See 7:37. "µ2 is the desired proportion of the test group because we don't have it yet" We want to see a change that is greater than the MDE (previously worked out at 0.02), so the mean desired proportion of the test group would be the mean dp of the control group + the mde.