Finding the Third Proportional to 209,560 and 428,804

Step by Step Solution

1. Step 1: Write the proportion equation
   209,560 : 428,804 = 428,804 : x
2. Step 2: Convert to fraction form
   209,560/428,804 = 428,804/x
3. Step 3: Cross multiply
   209,560x = 428,804 × 428,804
4. Step 4: Simplify right side
   209,560x = 183,872,870,416
5. Step 5: Solve for x
   x = 183,872,870,416/209,560
6. Step 6: Final answer
   x = 877,423.51