Finding the Third Proportional to 139,717 and 209,585

Step by Step Solution

1. Step 1: Write the proportion equation
   139,717 : 209,585 = 209,585 : x
2. Step 2: Convert to fraction form
   139,717/209,585 = 209,585/x
3. Step 3: Cross multiply
   139,717x = 209,585 × 209,585
4. Step 4: Simplify right side
   139,717x = 43,925,872,225
5. Step 5: Solve for x
   x = 43,925,872,225/139,717
6. Step 6: Final answer
   x = 314,391.75