6400 dollars is placed in an account with an annual interest rate of 6.25%. How much will be in the account after 20 years, to the nearest cent?Answer:
Q. 6400 dollars is placed in an account with an annual interest rate of 6.25%. How much will be in the account after 20 years, to the nearest cent?Answer:
Identify values: Identify the initial principal amount, the annual interest rate, and the time period.The initial principal amount P is $6400, the annual interest rate r is 6.25%, and the time period t is 20 years.
Convert rate to decimal: Convert the annual interest rate from a percentage to a decimal.To convert the rate to a decimal, divide by 100.r=1006.25%=0.0625
Use compound interest formula: Determine the formula to calculate the future value of the investment using compound interest.The formula for compound interest is A=P(1+r/n)(nt), where A is the amount of money accumulated after n years, including interest, P is the principal amount, r is the annual interest rate (decimal), n is the number of times that interest is compounded per year, and t is the time the money is invested for in years.
Assume compounding frequency: Since the problem does not specify the compounding frequency, assume that it is compounded annually n=1.n=1 (compounded annually)
Substitute values into formula: Substitute the values into the compound interest formula to calculate the future value. A=6400(1+0.0625/1)(1×20)
Simplify and calculate exponent: Simplify the expression inside the parentheses and then calculate the exponent.A=6400(1+0.0625)20A=6400(1.0625)20
Calculate future value: Calculate the future value using the simplified formula.A=6400×(1.0625)20A=6400×3.34885 (rounded to five decimal places)A=21432.64 (rounded to the nearest cent)
Check for errors: Check the calculation for any mathematical errors.Re-evaluate the expression to ensure that there are no errors in the calculation.A=6400×(1.0625)20A=6400×3.34885A=21432.64The calculation appears to be correct.
More problems from Exponential growth and decay: word problems