When using scientific notation, the number (that is not 10 to the nth power) is always between 1 and 10.
For 772,000.0, I've added the decimal to the correct place. In order to get a number between 1 and 10, we will need to move the decimal 5 places. This leaves us with 7.72 x 10^5.
But, as I see that the answer above is not an option, and the only correct answer would be A, It is the only one between 1 and 10, I feel that there may be a mistake. For A to be correct, the original number would be 7,720,000,000.
Best answer: A
Hope this helps!! :)