Answer: To solve this problem, we need to use the continuous compound interest formula:
A = Pe^(rt)
where A is the amount in the account, P is the initial principal, e is the mathematical constant e (approximately 2.71828), r is the annual interest rate (as a decimal), and t is the time in years.
For Michael's account, we have:
A = 1000e^(0.0475t)
For Peter's account, we have:
A = 1200e^(0.0425t)
We want to find the time it takes for each account to reach $1,800. So we can set up the following equations:
1000e^(0.0475t) = 1800
1200e^(0.0425t) = 1800
We can solve each equation for t by taking the natural logarithm of both sides and isolating t:
ln(1000) + 0.0475t = ln(1800)
ln(1200) + 0.0425t = ln(1800)
Subtracting ln(1000) or ln(1200) from both sides, we get:
0.0475t = ln(1800) - ln(1000)
0.0425t = ln(1800) - ln(1200)
Dividing both sides by the interest rate and simplifying, we get:
t = (ln(1800) - ln(1000)) / 0.0475 ≈ 10.16 years for Michael's account
t = (ln(1800) - ln(1200)) / 0.0425 ≈ 10.62 years for Peter's account
Therefore, Michael's account will grow to $1,800 first, after about 10 years (rounded to the nearest whole number).
Explanation: