Finding the Fourth Proportional to 7,143.42, 9,861.78 and 4,311.30

Step by Step Solution

1. Step 1: Write the proportion equation
   7,143.42 : 9,861.78 = 4,311.30 : x
2. Step 2: Convert to fraction form
   7,143.42/9,861.78 = 4,311.30/x
3. Step 3: Cross multiply
   7,143.42x = 9,861.78 × 4,311.30
4. Step 4: Simplify right side
   7,143.42x = 42,517,092.11
5. Step 5: Solve for x
   x = 42,517,092.11/7,143.42
6. Step 6: Final answer
   x = 5,951.92