Answer these questions about the interest calculation s.

Which account earned the most inter est, and how much more did it earn? Now move the cursor to cell C4, which holds the Account B interes t rate. Enter a new interest rate of 4.1 % without the percent symbol.

In each of the following compound interest equations with t representing the account term, determine the number of times the account is compounded per year and the interest rate percent. $6900=6000(1.006)^{6 t}$

At the end of 10 months, the balance of an account earning annual simple interest is $2100. a. If, at the end of 18 mo, the balance is$ 2180, how much money was originally in the account?
b. What is the annual rate of interest?

The total amount of money in a bank account paying compound interest can be determined by the formula $A=P\left(1+\frac{r}{n}\right)^{n t}$, where $P$ is the principal (amount deposited), $r$ is the annual rate of interest expressed as a decimal, $n$ is the number of times the interest is compounded in one year, and $t$ is the time in years. Determine the total amount of money in an account at the end of 4 months if the original sum deposited was $\$ 2550$, the interest rate is $8 \%$, compounded 4 times a year, and no money is deposited or withdrawn.

The Mejias have a $60,000 mortgage loan from Home Loan Bank at an interest rate of 11% for 25 years. Use the table on page 645 to find the monthly payment and the total interest charged.

Complete the table below. $$ \begin{matrix} \text{}{Amount \ invested \ \times} & \text{Annual interest rate=} & \text{Annual simple interest}\\ \text{\$400} & \text{7.5\\%} & \text{?}\\ \end{matrix} $$

In each of the following compound interest equations with t representing the account term, determine the number of times the account is compounded per year and the interest rate percent. $268.57=100(1.025)^{2 t}$

In each of the following compound interest equations with t representing the account term, determine the number of times the account is compounded per year and the interest rate percent. $15669.93=10000(1.00375)^{12 t}$

In each of the following compound interest equations with t representing the account term, determine the number of times the account is compounded per year and the interest rate percent. $2254=2000(1.002)^{12 t}$

Tanjay invests $\$ 100$ and earns interest at a rate of $4 \%$ per year for 10 years. Eda invests $\$ 100$ and earns interest at a rate of $2 \%$ every 6 months for 10 years. a) Calculate the value of both investments. b) Explain why Eda's investment is worth more at the end of 10 years.

Rewrite the following program to use the symbolic constant PRIME in place of the value 0.04 used in the program:

#include <iostream>

using namespace std;
int main() {
    float prime, amount, interest;
    prime = 0.04; // prime interest rate
    cout << < Enter the amount: ";
    cin >> amount;
    interest = prime * amount;
    cout << "The interest earned is" <<
        interest << " dollars" << endl;
    return 0;
}

A person deposits money into a retirement account, which pays $7\%$ interest compounded continuously, at a rate of $\$1000$ per year for $20$ years. Calculate:

(c ) The interest earned during the $20$ years.

Interest on a credit card’s unpaid balance is calculated using the average daily balance. Suppose that netBalance is the balance shown in the bill, payment is the payment made, d1 is the number of days in the billing cycle, and d2 is the number of days payment is made before billing cycle. Then, the average daily balance is:

$$averageDailyBalance = (netBalance * d1 – payment * d2) / d1$$

If the interest rate per month is, say, $0.0152$, then the interest on the unpaid balance is:

$$interest = averageDailyBalance * 0.0152$$

Write a program that accepts as input $netBalance, payment, d1, d2,$ and interest rate per month. The program outputs the interest. Format your output to two decimal places.

Lodi Enterprises uses an after-tax MARR of 15% per year. If the company’s effective tax rate (federal, state, and local taxes) is 38%, determine the company’s before-tax MARR.