Finding the Third Proportional to 259,761 and 390,403.50

Step by Step Solution

1. Step 1: Write the proportion equation
   259,761 : 390,403.50 = 390,403.50 : x
2. Step 2: Convert to fraction form
   259,761/390,403.50 = 390,403.50/x
3. Step 3: Cross multiply
   259,761x = 390,403.50 × 390,403.50
4. Step 4: Simplify right side
   259,761x = 152,414,892,812.25
5. Step 5: Solve for x
   x = 152,414,892,812.25/259,761
6. Step 6: Final answer
   x = 586,750.49