Finding the Third Proportional to 90,280 and 139,720

Step by Step Solution

1. Step 1: Write the proportion equation
   90,280 : 139,720 = 139,720 : x
2. Step 2: Convert to fraction form
   90,280/139,720 = 139,720/x
3. Step 3: Cross multiply
   90,280x = 139,720 × 139,720
4. Step 4: Simplify right side
   90,280x = 19,521,678,400
5. Step 5: Solve for x
   x = 19,521,678,400/90,280
6. Step 6: Final answer
   x = 216,234.81