Question

I'll give brainliest if you show your work. Plz answer quickly.
Nolan used the following procedure to find an estimate for the square root of 18.
Step 1: Since 4^2=16 and 5^2= 25 and 16 < 18 < 25, the square root of 18 is between 4 and 5.
4.1^2=16.81
4.2^2=17.64
4.3^2=18.49
4.4^2=19.36
Step 3: Since 18.49 rounds to 18, 4.3 is the best approximation for the square root of 18.
In which step, if any, did Nolan make an error?
A) In step 1, the square root of 18.
is between 4 and 5 because the square root of 18 equals about 20 and 4 times 5= 20.
B) In step 2, he made a calculation error when squaring.
C) In step 3, he should have determined which square is closest to 18.
D) Nolan did not make an error.

Answer 1

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.

Answer 2

 C) In step 3, he should have determined which square is closest to 18.