Finding the Third Proportional to 291,843 and 639,042.75

Step by Step Solution

1. Step 1: Write the proportion equation
   291,843 : 639,042.75 = 639,042.75 : x
2. Step 2: Convert to fraction form
   291,843/639,042.75 = 639,042.75/x
3. Step 3: Cross multiply
   291,843x = 639,042.75 × 639,042.75
4. Step 4: Simplify right side
   291,843x = 408,375,636,327.56
5. Step 5: Solve for x
   x = 408,375,636,327.56/291,843
6. Step 6: Final answer
   x = 1,399,299.06