Finding the Third Proportional to 478,926 and 639,066

Step by Step Solution

1. Step 1: Write the proportion equation
   478,926 : 639,066 = 639,066 : x
2. Step 2: Convert to fraction form
   478,926/639,066 = 639,066/x
3. Step 3: Cross multiply
   478,926x = 639,066 × 639,066
4. Step 4: Simplify right side
   478,926x = 408,405,352,356
5. Step 5: Solve for x
   x = 408,405,352,356/478,926
6. Step 6: Final answer
   x = 852,752.52