ANSWER:
$148,655.8
STEP-BY-STEP EXPLANATION:
Given:
Original salary = $28,000
Increase per year = 3%
The sum of all the earnings would be the sum of the original salary, the salary after 1 year, the salary after 2 years, the salary after 3 years and the salary after 4 years.
The salary in each year is calculated by multiplying the original salary by the increase raised after n years, just like this:
[tex]\begin{gathered} s_n=28000\cdot(1+3\%)^n_{} \\ s_n=28000\cdot(1+0.03)^n_{} \\ s_n=28000\cdot(1.03)^n_{} \end{gathered}[/tex]Therefore, the total earnings would be as follows:
[tex]\begin{gathered} t=28000+28000\cdot(1.03)^1+28000\cdot(1.03)^2+28000\cdot(1.03)^3+28000\cdot(1.03)^4 \\ t=28000+28840+29705.2+30596.4+31514.2 \\ t=148655.8 \end{gathered}[/tex]Therefore, the earnings in the first 5 years of MARla is $148,655.8