The 5 is in the tenths place, the 3 is in the hundredths place, and the 9 is in the thousandths place. So, to round to the hundredths place, we would look at the number after the 3, which is 9. Because 9 is greater than 4, we change add 1 to the 3, making it 4. So the correct answer is 78.54. However, if instead of 9 the number after the hundredths place was lower than 5, the 3 would stay 3, making the answer 78.53. But the correct answer in this case is 78.539.