Finding the Fourth Proportional to 128,702.72, 177,614.56 and 72,112

Step by Step Solution

1. Step 1: Write the proportion equation
   128,702.72 : 177,614.56 = 72,112 : x
2. Step 2: Convert to fraction form
   128,702.72/177,614.56 = 72,112/x
3. Step 3: Cross multiply
   128,702.72x = 177,614.56 × 72,112
4. Step 4: Simplify right side
   128,702.72x = 12,808,141,150.72
5. Step 5: Solve for x
   x = 12,808,141,150.72/128,702.72
6. Step 6: Final answer
   x = 99,517.25