Questions: Solve for the missing item in the following.
Note: Do not round intermediate calculations. Round your answer to the nearest whole percent.
Principal Interest rate Time Simple interest
5,400 % 19 months 342
Transcript text: Solve for the missing item in the following.
Note: Do not round intermediate calculations. Round your answer to the nearest whole percent.
\begin{tabular}{|c|c|c|c|c|c|}
\hline \multicolumn{2}{|l|}{ Principal } & Interest rate & Time & \multicolumn{2}{|l|}{ Simple interest } \\
\hline \$ & 5,400 & \% & 19 months & \$ & 342 \\
\hline
\end{tabular}
Solution
Solution Steps
To find the missing interest rate in a simple interest problem, we can use the formula for simple interest: I=P×r×t, where I is the interest, P is the principal, r is the interest rate, and t is the time in years. We need to solve for r. First, convert the time from months to years. Then, rearrange the formula to solve for r and calculate it using the given values.
Step 1: Identify the Known Values
We are given the principal amount P=5400, the simple interest I=342, and the time in months t=19.
Step 2: Convert Time to Years
Since the time is given in months, we need to convert it to years. The conversion is done by dividing the number of months by 12:
t=1219≈1.5833 years
Step 3: Use the Simple Interest Formula
The formula for simple interest is:
I=P×r×t
We need to solve for the interest rate r. Rearranging the formula gives:
r=P×tI
Step 4: Calculate the Interest Rate
Substitute the known values into the formula:
r=5400×1.5833342≈0.0400
Convert the interest rate to a percentage by multiplying by 100:
r=0.0400×100=4.00%