Finding the Third Proportional to 121,308 and 259,240.50

Step by Step Solution

1. Step 1: Write the proportion equation
   121,308 : 259,240.50 = 259,240.50 : x
2. Step 2: Convert to fraction form
   121,308/259,240.50 = 259,240.50/x
3. Step 3: Cross multiply
   121,308x = 259,240.50 × 259,240.50
4. Step 4: Simplify right side
   121,308x = 67,205,636,840.25
5. Step 5: Solve for x
   x = 67,205,636,840.25/121,308
6. Step 6: Final answer
   x = 554,008.28