Finding the Fourth Proportional to 28,123.60, 42,186.16 and 12,320.50

Step by Step Solution

1. Step 1: Write the proportion equation
   28,123.60 : 42,186.16 = 12,320.50 : x
2. Step 2: Convert to fraction form
   28,123.60/42,186.16 = 12,320.50/x
3. Step 3: Cross multiply
   28,123.60x = 42,186.16 × 12,320.50
4. Step 4: Simplify right side
   28,123.60x = 519,754,584.28
5. Step 5: Solve for x
   x = 519,754,584.28/28,123.60
6. Step 6: Final answer
   x = 18,481.08