Finding the Third Proportional to 209,567 and 428,818

Step by Step Solution

1. Step 1: Write the proportion equation
   209,567 : 428,818 = 428,818 : x
2. Step 2: Convert to fraction form
   209,567/428,818 = 428,818/x
3. Step 3: Cross multiply
   209,567x = 428,818 × 428,818
4. Step 4: Simplify right side
   209,567x = 183,884,877,124
5. Step 5: Solve for x
   x = 183,884,877,124/209,567
6. Step 6: Final answer
   x = 877,451.49