The statistical functions behind the A/B reporting.

Usage

Given an the user numbers and conversion rates for a couple of variants ...

var a = {
	visitors: 1531,
	conversions: 576
}

var b = {
	visitors: 1627,
	conversions: 627
}

We can calculate our confidence in the stats for this :-

confidence.conversionRate(1531, 576)   // 0.37622 - i.e. 37% conversion rate

confidence.zScore(a, b)   // z-score of -0.5292

Run make test for the full set of functions.