Finding the Fourth Proportional to 664,401.96, 996,761.70 and 215,123.31

Step by Step Solution

1. Step 1: Write the proportion equation
   664,401.96 : 996,761.70 = 215,123.31 : x
2. Step 2: Convert to fraction form
   664,401.96/996,761.70 = 215,123.31/x
3. Step 3: Cross multiply
   664,401.96x = 996,761.70 × 215,123.31
4. Step 4: Simplify right side
   664,401.96x = 214,426,676,185.23
5. Step 5: Solve for x
   x = 214,426,676,185.23/664,401.96
6. Step 6: Final answer
   x = 322,736.37