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In case of class interpolation we look at which input threshold (lower or higher) the value is closest to, and the output responding to that threshold will be the output. Using the example bellow below it mean for an input 0 the output will be 0, for input 160 output will be 2, for input 499 output will be 5. When the input falls exactly between the two thresholds, it will be rounded up, so for input 500 the output will be 6.
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