Final answer:
When comparing decimal numbers 0.78 and 0.708, 0.78 is greater than 0.708 because the digit '8' in the hundredths place of 0.78 is greater than the digit '0' in 0.708.
Step-by-step explanation:
When comparing two decimal numbers, one way to determine which is larger is to compare the digits from left to right. In this case, the numbers 0.78 and 0.708 are being compared. Looking at the digits after the decimal point, 7 in the first position is the same for both numbers. However, in the second position, there is an 8 in 0.78, which is larger than the 0 in the second position of 0.708. Therefore, using this comparison, 0.78 is greater than 0.708. So, the correct symbol to complete the comparison is > (greater than).
Accordingly, the answer to the comparison question is:
0.78 > 0.708