Finding the Third Proportional to 259,920 and 558,517.50

Step by Step Solution

1. Step 1: Write the proportion equation
   259,920 : 558,517.50 = 558,517.50 : x
2. Step 2: Convert to fraction form
   259,920/558,517.50 = 558,517.50/x
3. Step 3: Cross multiply
   259,920x = 558,517.50 × 558,517.50
4. Step 4: Simplify right side
   259,920x = 311,941,797,806.25
5. Step 5: Solve for x
   x = 311,941,797,806.25/259,920
6. Step 6: Final answer
   x = 1,200,145.42