Finding the Fourth Proportional to 128,600.72, 177,438.12 and 72,002.96

Step by Step Solution

1. Step 1: Write the proportion equation
   128,600.72 : 177,438.12 = 72,002.96 : x
2. Step 2: Convert to fraction form
   128,600.72/177,438.12 = 72,002.96/x
3. Step 3: Cross multiply
   128,600.72x = 177,438.12 × 72,002.96
4. Step 4: Simplify right side
   128,600.72x = 12,776,069,856.84
5. Step 5: Solve for x
   x = 12,776,069,856.84/128,600.72
6. Step 6: Final answer
   x = 99,346.80