find the error a classmate is calculating the amount in a savings account after 10 years. the deposit is…

find the error a classmate is calculating the amount in a savings account after 10 years. the deposit is $13,000 and the annual simple - interest rate is 2%. the work is shown below.\na = p(1+rn)\na = 13000(1 + 0.2×10)\na = 39000\n\ncomplete the explanation.\nthe classmate substituted for r. i can remind my classmate that to find the interest rate as a decimal, they should divide the rate by not

find the error a classmate is calculating the amount in a savings account after 10 years. the deposit is $13,000 and the annual simple - interest rate is 2%. the work is shown below.\na = p(1+rn)\na = 13000(1 + 0.2×10)\na = 39000\n\ncomplete the explanation.\nthe classmate substituted for r. i can remind my classmate that to find the interest rate as a decimal, they should divide the rate by not

Answer

Explanation:

Step1: Identify the simple - interest formula error

The correct simple - interest formula for the amount $A$ is $A = P(1+rt)$, where $P$ is the principal amount, $r$ is the annual interest rate (in decimal form), and $t$ is the time in years. The classmate used $r = 0.2$ instead of converting the $2%$ interest rate correctly.

Step2: Correct conversion of percentage to decimal

To convert a percentage to a decimal, we divide the percentage value by 100. For a $2%$ interest rate, $r=\frac{2}{100}=0.02$, not 0.2.

Answer:

The classmate substituted $0.2$ for $r$. I can remind my classmate that to find the interest rate as a decimal, they should divide the rate by $100$, not $10$.