Ella invested $4,900 in an account paying an interest rate of 3% compounded monthly. Assuming no deposits or withdrawals are made, how long would it take, to the nearest tenth of a year, for the value of the account to reach $5,920?​

Respuesta :

Answer:

It would take 6 years for the value of the account to reach $5,920

Step-by-step explanation:

Principal Amount = $4900

Interest rate r = 3% = 0.03

Compounded monthly = n=12

Time t =?

Future Value = $5920

We can find time using formula: [tex]A=P(1+\frac{r}{n})^{nt}[/tex]

Putting values and solving:

[tex]A=P(1+\frac{r}{n})^{nt}\\5920=4900(1+\frac{0.03}{12})^{12t} \\5920=4900(1+0.0025)^{12t}\\5920=4900(1.0025)^{12t}\\\frac{5920}{4900}= (1.0025)^{12t}\\1.21=(1.0025)^{12t}[/tex]

Applying exponent rule; [tex]a=b^c\\c\:ln(b)=ln(a)[/tex]

[tex]12t\:ln(1.0025)=ln(1.21)\\12t\:(0.00249)=0.19062\\t=\frac{0.19062}{12*0.00249}\\t=6.3\approx6[/tex]

So, It would take 6 years for the value of the account to reach $5,920