Bill's method is wrong since 3% is equivalent to 0.03 or 3/100 and not 1.3 so this is where the mistake is. Moreover, Bill's method is not only wrong but also incomplete.
In order to increase 150 by 3% you will have to determine how much is 3% of 150 to have it increased by that specific amount.
<u>Calculations:</u>
150 x 0.03 = 4.5
Now that we know 4.5 is 3% of 150, we can add 4.5 to 150 to increase it by 3%.
