Question

A collector’s item is purchased for $150 and its value increases by 3% each year. Which graph can be used to determine approximately how many years it will take for the value to double?





A collector’s item is purchased for $150 and its value increases by 3% each year. Which graph can be used to determine approximately how many years it will take for the value to double?

Answer 1

Use the exponential growth curve y = 150(1.03)^t and the horizontal line y = 300. The intersection of those two graphs gives the doubling time.

Solve 150(1.03)^t = 300:
t = ln(2) / ln(1.03) ≈ 23.45 years (about 23 years 5 months).