Approximately how long will it take for $700 to double if it is invested at 4% annual
interest, compounded continuously?
Round your final answer to the nearest whole year and do not label units.

Respuesta :

Answer: 17 years

Step-by-step explanation:

Exponential equation for compund amount( compunded continuously):

[tex]A=Pe^{rt}[/tex] , where P= Principal value , r= rate of interest , t= time.

Given: A= 2P

r =4%= 0.04

To find : t

Substitute all values in the formula , we get

[tex]2P=Pe^{0.04t}\\\\\Rightarrow\ 2=e^{0.04t}[/tex]

Taking natural log on both sides

[tex]\ln2=\ln e^{0.04t }\\\\\Rightarrow\ 0.693147=0.04t\\\\\Rightarrow\ t=\dfrac{ 0.693147}{0.04}\\\\\Rightarrow\ t=17.3286\approx17[/tex]

hence, it will take 17 years (approx).