after 3 months, $30,800 deposited in a savings account with simple interest had grown to a total of $31,031…

after 3 months, $30,800 deposited in a savings account with simple interest had grown to a total of $31,031. what was the interest rate? use the formula i = prt, where i is the interest earned, p is the principal (starting amount), r is the interest rate expressed as a decimal, and t is the time in years.

after 3 months, $30,800 deposited in a savings account with simple interest had grown to a total of $31,031. what was the interest rate? use the formula i = prt, where i is the interest earned, p is the principal (starting amount), r is the interest rate expressed as a decimal, and t is the time in years.

Answer

Explanation:

Step1: Calculate the interest earned

The interest $i$ is the final amount minus the principal. So $i=31031 - 30800=231$.

Step2: Convert time to years

The time $t$ is 3 months. Since there are 12 months in a year, $t=\frac{3}{12}=0.25$ years. The principal $p = 30800$.

Step3: Solve for the interest rate $r$

Using the formula $i = prt$, we can solve for $r$. Rearranging the formula gives $r=\frac{i}{pt}$. Substitute $i = 231$, $p = 30800$ and $t=0.25$ into the formula: $r=\frac{231}{30800\times0.25}=\frac{231}{7700}=0.03$.

Step4: Convert the decimal to a percentage

To convert the decimal to a percentage, multiply by 100. So the interest rate is $r = 0.03\times100 = 3%$.

Answer:

$3%$