Finding the Third Proportional to 426,397.50 and 638,940

Step by Step Solution

1. Step 1: Write the proportion equation
   426,397.50 : 638,940 = 638,940 : x
2. Step 2: Convert to fraction form
   426,397.50/638,940 = 638,940/x
3. Step 3: Cross multiply
   426,397.50x = 638,940 × 638,940
4. Step 4: Simplify right side
   426,397.50x = 408,244,323,600
5. Step 5: Solve for x
   x = 408,244,323,600/426,397.50
6. Step 6: Final answer
   x = 957,426.64