Answer:
The formula for calculating simple interest is:
I = P * r * t
where I is the interest earned, P is the principal (the amount deposited), r is the interest rate, and t is the time period (in years).
In this case, we have:
P = $4,000
r = 2.12% = 0.0212 (expressed as a decimal)
t = 1 year
So, the interest earned is:
I = $4,000 * 0.0212 * 1 = $84.80
To find the balance after one year, we simply add the interest to the principal:
Balance = $4,000 + $84.80 = $4,084.80
Therefore, Sally's balance after one year is $4,084.80.
Explanation: