Finding the Third Proportional to 208,900 and 428,860

Step by Step Solution

1. Step 1: Write the proportion equation
   208,900 : 428,860 = 428,860 : x
2. Step 2: Convert to fraction form
   208,900/428,860 = 428,860/x
3. Step 3: Cross multiply
   208,900x = 428,860 × 428,860
4. Step 4: Simplify right side
   208,900x = 183,920,899,600
5. Step 5: Solve for x
   x = 183,920,899,600/208,900
6. Step 6: Final answer
   x = 880,425.56