Answer
$F$
Work Step by Step
A scientific form of a number is:
$N=a\times 10^n$,
where $1\leq a<10$ and $n$ is integer.
For the first part of the scientific notation, you have to determine the number $a$. We take $40,500,000$ and divide it by $10^n$ so that we get $a=4.05$. Now you will count how many times you have to move the decimal to get $a$, and you will see that you have to move the decimal $7$ places. That is now your exponent $n=7$, so your answer is now
$40,500,000=4.05 \times 10^{7}$
