It is estimated that the city of Houston, Texas, will double in size every 35 years. If the population is currently 2.4 million people, how many people will there be in 20 years? 4.8 million

It is estimated that the city of Houston, Texas, will double in size every 35 years:
P=Po(2)^(t/35)

If the population is currently 2.4 million people:
Po=2.4 millions

How many people will there be in 20 years?
t=20 years, P=?

P=(2.4 millions)(2)^(t/35)

P=(2.4 millions)(2)^(20/35)
P=(2.4 millions)(2)^(0.571428571)
P=(2.4 millions)(1.485994289)
P=3.566386294 millions
P=3.6 millions

Answer: There will be 3.6 million people in 20 years.