Exercise 3: šœ‡1āˆ’šœ‡2

The value for the difference of (šœ‡1āˆ’šœ‡2) should be replaced by the value of this difference under the null hypothesis.

Can somebody please explain what šœ‡1and šœ‡2stands for In the ex3? My understanding was that we are using time user spends on the page, as a null hypothesis but apparently this is not the case.

Hi @tsh!

šœ‡1and šœ‡2 stand for the true average session duration for the control and variation populations (not samples, in that case x_bar is used) respectively. The null hypothesis is that there is NOT a difference between these values so the difference of (šœ‡1āˆ’šœ‡2) is equal to zero under the null hypothesis.

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Perfect, succinct answer, thanks!

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