Finding the Third Proportional to 78,487.50 and 100,780.50

Step by Step Solution

1. Step 1: Write the proportion equation
   78,487.50 : 100,780.50 = 100,780.50 : x
2. Step 2: Convert to fraction form
   78,487.50/100,780.50 = 100,780.50/x
3. Step 3: Cross multiply
   78,487.50x = 100,780.50 × 100,780.50
4. Step 4: Simplify right side
   78,487.50x = 10,156,709,180.25
5. Step 5: Solve for x
   x = 10,156,709,180.25/78,487.50
6. Step 6: Final answer
   x = 129,405.44