Finding the Third Proportional to 129,216 and 274,087.50

Step by Step Solution

1. Step 1: Write the proportion equation
   129,216 : 274,087.50 = 274,087.50 : x
2. Step 2: Convert to fraction form
   129,216/274,087.50 = 274,087.50/x
3. Step 3: Cross multiply
   129,216x = 274,087.50 × 274,087.50
4. Step 4: Simplify right side
   129,216x = 75,123,957,656.25
5. Step 5: Solve for x
   x = 75,123,957,656.25/129,216
6. Step 6: Final answer
   x = 581,382.78