Finding the Fourth Proportional to 128,826.72, 177,780.22 and 72,238.10

Step by Step Solution

1. Step 1: Write the proportion equation
   128,826.72 : 177,780.22 = 72,238.10 : x
2. Step 2: Convert to fraction form
   128,826.72/177,780.22 = 72,238.10/x
3. Step 3: Cross multiply
   128,826.72x = 177,780.22 × 72,238.10
4. Step 4: Simplify right side
   128,826.72x = 12,842,504,240.89
5. Step 5: Solve for x
   x = 12,842,504,240.89/128,826.72
6. Step 6: Final answer
   x = 99,688.20