Finding the Fourth Proportional to 3,900.22, 5,382.32 and 2,131.87

Step by Step Solution

1. Step 1: Write the proportion equation
   3,900.22 : 5,382.32 = 2,131.87 : x
2. Step 2: Convert to fraction form
   3,900.22/5,382.32 = 2,131.87/x
3. Step 3: Cross multiply
   3,900.22x = 5,382.32 × 2,131.87
4. Step 4: Simplify right side
   3,900.22x = 11,474,406.54
5. Step 5: Solve for x
   x = 11,474,406.54/3,900.22
6. Step 6: Final answer
   x = 2,941.99