Finding the Third Proportional to 399,607 and 856,212.50

Step by Step Solution

1. Step 1: Write the proportion equation
   399,607 : 856,212.50 = 856,212.50 : x
2. Step 2: Convert to fraction form
   399,607/856,212.50 = 856,212.50/x
3. Step 3: Cross multiply
   399,607x = 856,212.50 × 856,212.50
4. Step 4: Simplify right side
   399,607x = 733,099,845,156.25
5. Step 5: Solve for x
   x = 733,099,845,156.25/399,607
6. Step 6: Final answer
   x = 1,834,552.06