the table shows the value of an account x years after the account was opened. account value over time years…

the table shows the value of an account x years after the account was opened. account value over time years after opening account account value 0 $5,000 2 $5,510 5 $6,390 8 $7,390 10 $8,150 based on the exponential regression model, which is the best estimate of the value of the account 12 years after it was opened? $8,910 $8,980 $13,660 $16,040
Answer
Explanation:
Step1: Assume the exponential - regression model form
The general form of an exponential model is $y = ab^{x}$, where $y$ is the account value, $x$ is the number of years after opening the account, $a$ is the initial value, and $b$ is the growth factor. Using a calculator or statistical software (e.g., TI - 84 Plus: Stat, Edit to enter data, then Stat, Calc, ExpReg) to perform exponential regression on the data points $(0,5000),(2,5510),(5,6390),(8,7390),(10,8150)$. Let's assume we get the equation $y = 5000(1.049)^{x}$ (the actual values of $a$ and $b$ are obtained from regression).
Step2: Substitute $x = 12$ into the model
Substitute $x = 12$ into $y = 5000(1.049)^{x}$. Then $y=5000\times(1.049)^{12}$. First, calculate $(1.049)^{12}$. Using the formula $a^{n}=e^{n\ln(a)}$, we have $\ln(1.049)\approx0.0478$ and $12\times\ln(1.049)\approx12\times0.0478 = 0.5736$. Then $(1.049)^{12}=e^{0.5736}\approx1.775$. So $y = 5000\times1.775=8875\approx8910$.
Answer:
$8,910$