How to calculate the statistics used in the button example

[aaronshu]

1. At the end of the test, 90% of people that saw the green button clicked it, whereas 60% of the people that saw the blue button clicked it.

2. Now we need to ask, “If color wasn’t related to click rate, how likely was a 30% difference just by chance?” We can use statistics to calculate that probability. If there is less than a 5% probability that our results happened by chance, we have good evidence that green buttons get more clicks!

3. Statistically speaking, there is less than a 5% chance of that happening.

4. How did they calculate the probability of that happening? Thanks!

Click on the image to see it better

[_beowulf]

Bump. I’d love to see how this is done. I’m brushing up on my math skills in other areas ( not at probability yet), and am going to figure how to do these types of calculations.