Question

In 2010, there were approximately 296,000 smartphones sold in a certain country, and in 2019 there were approximately 1,541,000 smartphones sold in that country. Based on the average rate of change in the number of smartphones sold in the country per year from 2010 to 2019, which of the following is closest to the number of smartphones sold in the country in 2017?

Answer 1

Average rate = (1,541,000 − 296,000) / (2019 − 2010) = 1,245,000 / 9 ≈ 138,333.33 per year.

From 2010 to 2017 is 7 years, so estimate = 296,000 + 7×138,333.33 ≈ 296,000 + 968,333.33 ≈ 1,264,333.

Closest: about 1,264,000 smartphones.