Exercise 1: Comparing Two Measurement Errors — Possible Solution ==================================================================== COMPUTING BOTH ERRORS FOR EACH CASE ------------------------------ Case A: true value = 50.0, approximation = 50.5 absolute error = |50.5 - 50.0| = 0.5 relative error = 0.5 / 50.0 = 0.01 (1%) Case B: true value = 0.05, approximation = 0.055 absolute error = |0.055 - 0.05| = 0.005 relative error = 0.005 / 0.05 = 0.10 (10%) WHICH IS THE MORE SERIOUS PROBLEM ------------------------------ Case B is the more serious measurement problem, even though its absolute error (0.005) is one hundred times smaller in raw magnitude than Case A's absolute error (0.5). The relative error tells the real story: Case A is off by 1% of the true value, while Case B is off by a full 10% of its true value - ten times worse in relative terms, despite looking far smaller in absolute terms. WHY RELATIVE ERROR IS THE RIGHT LENS HERE ------------------------------ This chapter's own worked example (the 1,000,000.0 vs. 0.0001 true-value comparison) demonstrated the same pattern: absolute error alone doesn't distinguish between "practically perfect" and "completely unreliable" results, because it ignores the scale of the number being measured. Here, the same logic applies directly: a 0.5-unit error on a measurement around 50 is a much smaller proportional mistake than a 0.005-unit error on a measurement around 0.05, even though the raw numbers seem to suggest the opposite at first glance. Judging measurement quality by absolute error alone would incorrectly rank Case A as "worse," when relative error shows the true ranking is the reverse. WHY THIS WORKS AS AN ANSWER ------------------------------ The answer computes both error measures precisely for each case rather than estimating, correctly identifies that the smaller absolute error case is actually the more seriously wrong one in relative terms, and explains the conclusion using this chapter's own established reasoning about why relative error, not absolute error, is the meaningful measure of trustworthiness.