Given equation:
P=1500 (1.04)^x
When have to find x, when population, p=1900
Put value of P=1900 in above equation.
1900=1500(1.04)^x
Divide both sides by 1500
19/15=(1.04)^x
1.27=(1.04)^x
Take natural log.
ln(1.27)= ln(1.04)^x
ln(1.27)=x ln (1.04)
Divide both sides by ln (1.04)
x=6 years
Answer: 6 years