Finding the Fourth Proportional to 385,196.31, 531,572.22 and 215,419.50

Step by Step Solution

1. Step 1: Write the proportion equation
   385,196.31 : 531,572.22 = 215,419.50 : x
2. Step 2: Convert to fraction form
   385,196.31/531,572.22 = 215,419.50/x
3. Step 3: Cross multiply
   385,196.31x = 531,572.22 × 215,419.50
4. Step 4: Simplify right side
   385,196.31x = 114,511,021,846.29
5. Step 5: Solve for x
   x = 114,511,021,846.29/385,196.31
6. Step 6: Final answer
   x = 297,279.64