Nolan used the following procedure to find an estimate for .

Step 1: Since and and 16 < 18 < 25, is between 4 and 5.
Step 2: Since 18 is closer to 16, square the tenths closer to 4.

Step 3: Since 18.49 rounds to 18, 4.3 is the best approximation for .

In which step, if any, did Nolan make an error?
In step 1, is between 4 and 5 because 20 and .
In step 2, he made a calculation error when squaring.
In step 3, he should have determined which square is closest to 18.
Nolan did not make an error.