Mean, Median, Mode

ACT Math · Axiom Academy

Three different ways to answer "what's typical?" — and why the ACT expects you to know which one to reach for. 1. Mean — Spreading the Total Evenly The mean (what most people call the "average") takes every value, adds them up, and divides by how many there are. Picture it as a physical redistribution: take all seven quiz scores and pour them into one pool, then hand every student the same share back. Add every value, divide by the count For our 7 scores: 574 ÷ 7 = 82 2. Median — Sort First, Then Find the Middle The median is the value exactly in the middle once the data is sorted from smallest to largest. The rule splits into two cases depending on whether you have an odd or even number of values — and mixing these up is one of the most common ACT data-analysis mistakes. Sort the data. The median is the single value sitting exactly in the middle position — for 7 values, that's the 4th one. Sort the data. There's no single middle value, so the median is the average of the two values on either side of center. Sorted: 72, 72, 76, 80 , 86, 92, 96 — three values sit below 80, three sit above it, so the median is 80. Sorted: 58, 65, 65, 71 , 79, 84 — the middle two are 65 and 71, so the median is . Why the median survives outliers

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