Exponential Modelling Question

Question

A CT scan shows that the patient has a 3 cm tumor. After 25 days, the size of the tumor has has increased to 5.9 cm. What is the growth rate?

b = Answer (round to the nearest hundredth)

Percentage = Answer% (no decimal places)

Answer 1

The equation for exponential growth is

y= A(e^kt). where A is initial value, k is growth constant and t is time

5.9= 3.0(e^25k)

(5.9/3)= e^25k. Now take natural log of both sides

ln(1.997)= ln (e^25k)

ln 1.997= 25k

k= ln1.997/25

k=.027= 2.7%