Exponential vs. Linear Question 2

C=130x

C=105(1.2)^x

calculator allowed An advertiser is using one of the two models above to predict the number of clicks, $C$ , made $x$ weeks after a web banner ad is implemented. How many more clicks are predicted by the linear model than by the exponential model 8 weeks after the advertising campaign begins?

32

451

589

1{,}040

Approach

Substitute $x=8$ into the two given equations.

Linear model

C=130x

C=130(8)

C=1{,}040

Exponential model

C=105(1.2)^x

C=105(1.2)^8

C \approx 451

\text{Difference} = 1{,}040-451

= \boxed{589}