Answer
$6$ people
Work Step by Step
Step 1. Assume that there were $x$ number of people in the original group; then each person should share a cost of $\frac{480000}{x}$ dollars.
Step 2. Adding 4 more people, we have $x+4$ and each should pay $\frac{480000}{x+4}$ dollars.
Step 3. Based on the condition given, we have $\frac{480000}{x}-\frac{480000}{x+4}=32000$, which can be simplified to $\frac{15}{x}-\frac{15}{x+4}=4$
Step 4. Multiply $x(x+4)$ on both sides; we have $15(x+4)-15x=x(x+4)$ or $x^2+4x-60=0$, which can be factored as $(x-6)(x+10)=0$
Step 5. Discard the negative solution; we have $x=6$
