Answer:
Account A: Decreasing at 8 % per year
Account B: Decreasing at 10.00 % per year
Account B shows the greater percentage change
Step-by-step explanation:
Part A: Percent change from exponential formula
f(x) = 9628(0.92)ˣ
The general formula for an exponential function is
y = ab^x, where
b = the base of the exponential function.
if b < 1, we have an exponential decay function.
ƒ(x) decreases as x increases.
Account A is decreasing each year.
We can rewrite the formula for an exponential decay function as:
y = a(1 – b)ˣ, where
1 – b = the decay factor
b = the percent change in decimal form
If we compare the two formulas, we find
0.92 = 1 - b
b = 1 - 0.92 = 0.08 = 8 %
The account is decreasing at an annual rate of 8 %.
Part B. Percent change from table
The account is decreasing at an annual rate of 10.00 %.
Account B recorded a greater percentage change in the amount of money over the previous year.