Percentage of worldwide population smartphone usage

Question

In 2014, there were approximately 1.75x10^9 smartphones users worldwide. If the world's population in 2014 was about 7.19x10^9, determine the approximate percentage of the worldwide population that used a smartphone.

Answer 1

Solve this as a proportion:

 

1.75x10⁹ is to 7.19x10⁹ as x is to 100.

 

1.75x10⁹ / 7.19x10⁹ = x/100

 

x = 100 (1.75x10⁹ / 7.19x10⁹) ≅ 24.3%