Finding the Third Proportional to 292,876.50 and 639,456

Step by Step Solution

1. Step 1: Write the proportion equation
   292,876.50 : 639,456 = 639,456 : x
2. Step 2: Convert to fraction form
   292,876.50/639,456 = 639,456/x
3. Step 3: Cross multiply
   292,876.50x = 639,456 × 639,456
4. Step 4: Simplify right side
   292,876.50x = 408,903,975,936
5. Step 5: Solve for x
   x = 408,903,975,936/292,876.50
6. Step 6: Final answer
   x = 1,396,165.20