Finding the Fourth Proportional to 3,861.32, 5,789.39 and 3,121.83

Step by Step Solution

1. Step 1: Write the proportion equation
   3,861.32 : 5,789.39 = 3,121.83 : x
2. Step 2: Convert to fraction form
   3,861.32/5,789.39 = 3,121.83/x
3. Step 3: Cross multiply
   3,861.32x = 5,789.39 × 3,121.83
4. Step 4: Simplify right side
   3,861.32x = 18,073,475.77
5. Step 5: Solve for x
   x = 18,073,475.77/3,861.32
6. Step 6: Final answer
   x = 4,680.65