Question

question
given the following exponential function, identify whether the change represents growth or decay, and determine the percentage rate of increase or decrease.

$y = 99(0.91)^x$

answer
attempt 1 out of 2
growth % increase
submit answer
copyright ©2026 deltamath.com all rights reserved.
terms & policies

Explanation:

Step1: Identify growth/decay factor

The exponential function is in the form $y = a(b)^x$, where $b$ is the base. Here, $b = 0.91$. Since $0 < b < 1$, this represents decay.

Step2: Calculate percentage decrease

The percentage rate of decrease is found by $1 - b$, converted to a percentage.
$1 - 0.91 = 0.09 = 9\%$

Answer:

Decay, 9% decrease