Finding the Fourth Proportional to 78,216.20, 108,000.50 and 72,245.72

Step by Step Solution

1. Step 1: Write the proportion equation
   78,216.20 : 108,000.50 = 72,245.72 : x
2. Step 2: Convert to fraction form
   78,216.20/108,000.50 = 72,245.72/x
3. Step 3: Cross multiply
   78,216.20x = 108,000.50 × 72,245.72
4. Step 4: Simplify right side
   78,216.20x = 7,802,573,882.86
5. Step 5: Solve for x
   x = 7,802,573,882.86/78,216.20
6. Step 6: Final answer
   x = 99,756.49