The exponential equation that best represents the table of earnings is y = 60,000(0.95)^4.
Exponential equation shows a constant rate of increase of decrease over a period.
The exponential decrease equation is modeled by the formula:
y = a(1 - r)^x
Where y = the decreased value
a = the initial value
r = the annual decrease rate
x = the number of years involved since the initial year.
Mr. Whaley's company's earnings in 2009 = $60,000
The period of decrease each year = 4 years
The decrease between 2009 and 2010 = $3,000 ($60,000 - $57,000)
= 5% ($3,000/$60,000 x 100)
The decrease between 2010 and 2011 = $2,850 ($57,000 - $54,150)
= 5% ($2,850/$54,150 x 100)
We can assume this decrease rate to continue or check it out with other interval years.
y = 60,000(0.95)^4.