Answer:
C) In step 3, he should have determined which square is closest to 18.
Step-by-step explanation:
17.64 also rounds to 18. 17.64 differs from 18 by ...
18 -17.64 = 0.36
whereas 18.49 differs from 18 by ...
18.49 -18 = 0.49
Hence 17.64 is closer to 18 and we might expect 4.2 to be closer to √18 than is 4.3.
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The actual root of 18 is about 4.243, so 4.2 is a better approximation.
