document.write( "Question 1202635: Ali invests $14 800 in an account that earns interest compounded semi-annually for 8 years. She then takes all the money, which amounts to $17 063.24, and invests it in an account that earns interest compounded quarterly for 6 years. After the 14 years, the account is worth $18 846.11. What annual interest rate was Ali earning on each of the accounts? \n" ); document.write( "
Algebra.Com's Answer #837583 by math_tutor2020(3817)![]() ![]() ![]() You can put this solution on YOUR website! \n" ); document.write( "Compound interest formula \n" ); document.write( "A = P*(1+r/n)^(n*t)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "A = final amount \n" ); document.write( "P = deposit \n" ); document.write( "r = annual interest rate in decimal form \n" ); document.write( "n = compounding frequency \n" ); document.write( "t = number of years\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Use this given info \n" ); document.write( "\"Ali invests $14,800 in an account that earns interest compounded semi-annually for 8 years...which amounts to $17,063.24\" \n" ); document.write( "to determine: \n" ); document.write( "A = 17063.24 \n" ); document.write( "P = 14800 \n" ); document.write( "r = unknown \n" ); document.write( "n = 2 \n" ); document.write( "t = 8\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "A = P*(1+r/n)^(n*t) \n" ); document.write( "17063.24 = 14800*(1+r/2)^(2*8) \n" ); document.write( "17063.24 = 14800*(1+r/2)^16 \n" ); document.write( "17063.24/14800 = (1+r/2)^16 \n" ); document.write( "1.15292162 = (1+r/2)^16 \n" ); document.write( "(1+r/2)^16 = 1.15292162 \n" ); document.write( "1+r/2 = (1.15292162)^(1/16) \n" ); document.write( "1+r/2 = 1.00893337 \n" ); document.write( "r/2 = 1.00893337-1 \n" ); document.write( "r/2 = 0.00893337 \n" ); document.write( "r = 2*0.00893337 \n" ); document.write( "r = 0.01786674 \n" ); document.write( "r = 0.01787 \n" ); document.write( "The first account has an annual rate of about 1.787%\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "For the 2nd account, Ali has: \n" ); document.write( "A = 18846.11 \n" ); document.write( "P = 17063.24 \n" ); document.write( "r = unknown \n" ); document.write( "n = 4 \n" ); document.write( "t = 6\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Caution: The instructions mention After the 14 years, but we will not use t = 14 for the 2nd account. \n" ); document.write( "The money sits in the 2nd account for 6 years and not 14. \n" ); document.write( "The 14 refers to 8 years + 6 years = 14 years total.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "I'll skip the steps (since they will be similar to the ones shown above), but you should get r = 0.0166 to represent an annual rate of approximately 1.66% \n" ); document.write( " \n" ); document.write( " |