Finding the Third Proportional to 399,478.50 and 561,894

Step by Step Solution

1. Step 1: Write the proportion equation
   399,478.50 : 561,894 = 561,894 : x
2. Step 2: Convert to fraction form
   399,478.50/561,894 = 561,894/x
3. Step 3: Cross multiply
   399,478.50x = 561,894 × 561,894
4. Step 4: Simplify right side
   399,478.50x = 315,724,867,236
5. Step 5: Solve for x
   x = 315,724,867,236/399,478.50
6. Step 6: Final answer
   x = 790,342.58