Finding the Fourth Proportional to 7,142.38, 9,856.47 and 3,998.50

Step by Step Solution

1. Step 1: Write the proportion equation
   7,142.38 : 9,856.47 = 3,998.50 : x
2. Step 2: Convert to fraction form
   7,142.38/9,856.47 = 3,998.50/x
3. Step 3: Cross multiply
   7,142.38x = 9,856.47 × 3,998.50
4. Step 4: Simplify right side
   7,142.38x = 39,411,095.30
5. Step 5: Solve for x
   x = 39,411,095.30/7,142.38
6. Step 6: Final answer
   x = 5,517.92