Finding the Fourth Proportional to 3,900.27, 5,382.39 and 2,131.91

Step by Step Solution

1. Step 1: Write the proportion equation
   3,900.27 : 5,382.39 = 2,131.91 : x
2. Step 2: Convert to fraction form
   3,900.27/5,382.39 = 2,131.91/x
3. Step 3: Cross multiply
   3,900.27x = 5,382.39 × 2,131.91
4. Step 4: Simplify right side
   3,900.27x = 11,474,771.06
5. Step 5: Solve for x
   x = 11,474,771.06/3,900.27
6. Step 6: Final answer
   x = 2,942.05