Finding the Fourth Proportional to 12,432.42, 18,640.60 and 5,321.29

Step by Step Solution

1. Step 1: Write the proportion equation
   12,432.42 : 18,640.60 = 5,321.29 : x
2. Step 2: Convert to fraction form
   12,432.42/18,640.60 = 5,321.29/x
3. Step 3: Cross multiply
   12,432.42x = 18,640.60 × 5,321.29
4. Step 4: Simplify right side
   12,432.42x = 99,192,011.77
5. Step 5: Solve for x
   x = 99,192,011.77/12,432.42
6. Step 6: Final answer
   x = 7,978.50