Finding the Third Proportional to 243,279 and 387,404

Step by Step Solution

1. Step 1: Write the proportion equation
   243,279 : 387,404 = 387,404 : x
2. Step 2: Convert to fraction form
   243,279/387,404 = 387,404/x
3. Step 3: Cross multiply
   243,279x = 387,404 × 387,404
4. Step 4: Simplify right side
   243,279x = 150,081,859,216
5. Step 5: Solve for x
   x = 150,081,859,216/243,279
6. Step 6: Final answer
   x = 616,912.51