Finding the Fourth Proportional to 128,432.72, 177,244.04 and 71,840.72

Step by Step Solution

1. Step 1: Write the proportion equation
   128,432.72 : 177,244.04 = 71,840.72 : x
2. Step 2: Convert to fraction form
   128,432.72/177,244.04 = 71,840.72/x
3. Step 3: Cross multiply
   128,432.72x = 177,244.04 × 71,840.72
4. Step 4: Simplify right side
   128,432.72x = 12,733,339,449.31
5. Step 5: Solve for x
   x = 12,733,339,449.31/128,432.72
6. Step 6: Final answer
   x = 99,144.05