Answer:
600 people
Explanation:
We can use ratios to solve this problem.
Change the 30 minutes in to hours
30 minutes = .5 hours
75 people x people
---------------- = -----------------------
.5 hours 4 hours
Using cross products
75*4 = .5 *x
300 = .5x
Divide each side by .5
300/.5 = .5x/.5
600 =x