Xavier Fok

Regression analysis in plain English: how the line of best fit turns one number into a prediction, what the slope and r squared mean, and where the line lies.

How to tell a genuine seasonal pattern in your metrics from a reporting artefact caused by billing cycles, timezones, or pipeline quirks, with a practical checklist for solo operators.

Simpson’s paradox in plain English: how a trend reverses when you pool your groups, why a hidden confounder causes it, and how to catch it in your own data.

How to build an honest revenue forecast for a small business: the run rate baseline, forecasting your drivers, adding growth without fooling yourself, and always a range.

A practical way to report business metrics when your data is incomplete, delayed, or built on assumptions, without pretending you have more certainty than you do.

Skewness is why your average order looks bigger than any real order. Here is what it means, how to spot it with mean versus median, and what to report instead.

The normal distribution is the bell curve your stats shortcuts secretly assume. Here is what it is, why business data rarely fits, and how to check.

Why the customers who talk to you most and buy the most can quietly bias your product and pricing decisions, and how to catch it.

Percentiles read the tail your average hides, with no bell shape assumed. Here is what p50, p90, and p95 mean, when to trust them, and the traps.

Standard deviation is the single number for how far your values sit from their average. Here is what it measures, the rough rule you can lean on, and the traps.