In 2016, the population of the United States was approximately 3.24 x 10^8. It is expected that the population will be about 3.98 x 10^8 in 2050. Which shows the growth in population, written in scientific notation?

7.4 x 10^7

Step-by-step explanation:

3.98 x 10^8 - 3.24 x 10^8 = 0.74 x 10^8 (not scientific notation, because it isn't full number)

0.74 x 10^8 - --> 7.4 x 10^7

- got seven by counting the spaces it moved over (right decrease, while left increases)