Harmonic mean is the reciprocal of the arithmetic mean of the reciprocals of a set of numbers. It's often used in situations where you're dealing with rates or ratios, like when calculating the average speed of a round trip or the average resistance in a parallel circuit - because apparently some sadist decided arithmetic means weren't confusing enough on their own.

How to use it in a sentence

• I was trying to calculate the harmonic mean of my code's performance metrics, but then I realized I could just deploy it to production and let the users figure it out.

• My manager keeps talking about optimizing the harmonic mean of our team's velocity, but I'm pretty sure he just heard that phrase in a TED talk and has no idea what it actually means.

If you actually want to learn more...

• Harmonic Mean: Definition, Formula & Examples - This article dives into the nitty-gritty of harmonic means, complete with formulas and examples that might just make you appreciate arithmetic means a little more.

• When to use the harmonic mean - If you're still not convinced that harmonic means have any practical use outside of making your head hurt, this post explains when and why you might want to use them in real life (spoiler alert: it's not just to impress your Tinder date).

• Harmonic Mean: What Is It? - For those who prefer their math with a side of finance, this Investopedia article explains how harmonic means are used in the thrilling world of stock analysis and valuation (because apparently even Wall Street quants need a break from arithmetic means now and then).

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