Finding the Third Proportional to 292,819.50 and 639,342

Step by Step Solution

1. Step 1: Write the proportion equation
   292,819.50 : 639,342 = 639,342 : x
2. Step 2: Convert to fraction form
   292,819.50/639,342 = 639,342/x
3. Step 3: Cross multiply
   292,819.50x = 639,342 × 639,342
4. Step 4: Simplify right side
   292,819.50x = 408,758,192,964
5. Step 5: Solve for x
   x = 408,758,192,964/292,819.50
6. Step 6: Final answer
   x = 1,395,939.11