Question

I need help solving this problem

Answer 1

Use the given values in the compound interest formula to solve for time, n.

A is the final amount of money, $2800
P is the initial or starting amount $1900
i is the interest rate as a decimal 0.025
n is time in years since it annual.

2800 = 1900(1 + 0.025)^n

2800 = 1900(1.025)^n

2800/1900 = (1.025)^n

28/19 = (1.025)^n

take the natural log of both sides to solve for exponent.

ln(28/19) = ln(1.025^n)

power rule of logarithmic moves exponent

ln(28/19) = n*ln(1.025)

ln(28/19) / ln(1.025) = n

put into a calculator

15.7 years = n