Chapter 9 - Quadratic Functions and Equations - 9-7 Linear Quadratic, and Exponential Models - Practice and Problem-Solving Exercises - Page 592: 16

An exponential model fits the data. $y=5\times 0.4^x$

An exponential model fits the data. Write an exponential model $y=a.b^x$ The y-values have a common ratio of $0.4$. Let a = the initial value, $5$ Let b = the decay factor, $0.4$ We get, $y=5\times 0.4^x$