Finding the Fourth Proportional to 128,631, 177,510.78 and 72,060.60

Step by Step Solution

1. Step 1: Write the proportion equation
   128,631 : 177,510.78 = 72,060.60 : x
2. Step 2: Convert to fraction form
   128,631/177,510.78 = 72,060.60/x
3. Step 3: Cross multiply
   128,631x = 177,510.78 × 72,060.60
4. Step 4: Simplify right side
   128,631x = 12,791,533,313.27
5. Step 5: Solve for x
   x = 12,791,533,313.27/128,631
6. Step 6: Final answer
   x = 99,443.63