Finding the Fourth Proportional to 72,499.20, 108,748.80 and 50,380.80

Step by Step Solution

1. Step 1: Write the proportion equation
   72,499.20 : 108,748.80 = 50,380.80 : x
2. Step 2: Convert to fraction form
   72,499.20/108,748.80 = 50,380.80/x
3. Step 3: Cross multiply
   72,499.20x = 108,748.80 × 50,380.80
4. Step 4: Simplify right side
   72,499.20x = 5,478,851,543.04
5. Step 5: Solve for x
   x = 5,478,851,543.04/72,499.20
6. Step 6: Final answer
   x = 75,571.20