Finding the Fourth Proportional to 78,205.20, 107,985.30 and 72,234.72

Step by Step Solution

1. Step 1: Write the proportion equation
   78,205.20 : 107,985.30 = 72,234.72 : x
2. Step 2: Convert to fraction form
   78,205.20/107,985.30 = 72,234.72/x
3. Step 3: Cross multiply
   78,205.20x = 107,985.30 × 72,234.72
4. Step 4: Simplify right side
   78,205.20x = 7,800,287,909.62
5. Step 5: Solve for x
   x = 7,800,287,909.62/78,205.20
6. Step 6: Final answer
   x = 99,741.29