On a bar graph, village A's bar looks twice as tall as village B's
On a bar graph, village A's bar looks twice as tall as village B's. Naina says that means A has twice as many people as B. But the graph's axis starts at 90, not 0, and the real figures are A = 100, B = 95. Who is right?
Who do you think is right? Pick one.
The answer: No — A is only slightly more than B (100 vs 95); the axis not starting at 0 makes the gap look huge
Why
Naina is reading the bars the way bar graphs are USUALLY safe to read — a bar twice as tall means twice as much. That shortcut only works when the axis starts at zero, so that a bar's full height stands for its full value. This graph's axis starts at 90, so each bar only shows the part above 90: village A's bar is the stretch from 90 to 100 (10 units) and village B's is from 90 to 95 (5 units), which is why A's bar looks twice B's. But the actual populations are 100 and 95 — A has only about 5 percent more people, not twice as many. Test it: redraw the same two bars with the axis starting at 0 — they would be 100 tall and 95 tall, almost the same height, and the 'twice as big' impression disappears completely. The second option is right: A is only slightly larger than B; a bar graph whose axis does not start at zero turns a small difference into a big-looking one.
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