Finding the Third Proportional to 78,190.50 and 129,417.38

Step by Step Solution

1. Step 1: Write the proportion equation
   78,190.50 : 129,417.38 = 129,417.38 : x
2. Step 2: Convert to fraction form
   78,190.50/129,417.38 = 129,417.38/x
3. Step 3: Cross multiply
   78,190.50x = 129,417.38 × 129,417.38
4. Step 4: Simplify right side
   78,190.50x = 16,748,856,951.89
5. Step 5: Solve for x
   x = 16,748,856,951.89/78,190.50
6. Step 6: Final answer
   x = 214,205.78