Finding the Fourth Proportional to 28,123.56, 42,196.98 and 12,320.42

Step by Step Solution

1. Step 1: Write the proportion equation
   28,123.56 : 42,196.98 = 12,320.42 : x
2. Step 2: Convert to fraction form
   28,123.56/42,196.98 = 12,320.42/x
3. Step 3: Cross multiply
   28,123.56x = 42,196.98 × 12,320.42
4. Step 4: Simplify right side
   28,123.56x = 519,884,305.35
5. Step 5: Solve for x
   x = 519,884,305.35/28,123.56
6. Step 6: Final answer
   x = 18,485.72