Finding the Third Proportional to 218,698 and 478,386

Step by Step Solution

1. Step 1: Write the proportion equation
   218,698 : 478,386 = 478,386 : x
2. Step 2: Convert to fraction form
   218,698/478,386 = 478,386/x
3. Step 3: Cross multiply
   218,698x = 478,386 × 478,386
4. Step 4: Simplify right side
   218,698x = 228,853,164,996
5. Step 5: Solve for x
   x = 228,853,164,996/218,698
6. Step 6: Final answer
   x = 1,046,434.65