Step 1: Move the decimal point from its current position (the black dot) to a position immediately to the right of the first nonzero digit (the red dot).
1.3919413.92
Step 2: We moved the decimal point 7 spaces to the right. Therefore, the exponent on base 10 will be positive 7.Now we know that the:
Mantissa = 1.391941392
Exponent = 7
So, the solution is:
$$13919413.92 = \color{blue}{ 1.391941392} \cdot 10^{ \color{red}{ 7 }}$$