Finding the Third Proportional to 356,780 and 489,247.50

Step by Step Solution

1. Step 1: Write the proportion equation
   356,780 : 489,247.50 = 489,247.50 : x
2. Step 2: Convert to fraction form
   356,780/489,247.50 = 489,247.50/x
3. Step 3: Cross multiply
   356,780x = 489,247.50 × 489,247.50
4. Step 4: Simplify right side
   356,780x = 239,363,116,256.25
5. Step 5: Solve for x
   x = 239,363,116,256.25/356,780
6. Step 6: Final answer
   x = 670,898.36