Learn the basis for checking if a hypothesis — and your numbers — are reasonable.
Study the basics of hypothesis testing and confidence intervals.
Use Fermi estimates to get a handle on big quantities.
What’s the probability one stock will finish with a higher stock price than the other?
If the planes are numbered sequentially and you observe these three, how many planes are there likely to be?
First, we’ll answer: how can we tell if a model is consistent with real-world data?