Finding the Fourth Proportional to 3,900.16, 5,381.94 and 2,131.39

Step by Step Solution

1. Step 1: Write the proportion equation
   3,900.16 : 5,381.94 = 2,131.39 : x
2. Step 2: Convert to fraction form
   3,900.16/5,381.94 = 2,131.39/x
3. Step 3: Cross multiply
   3,900.16x = 5,381.94 × 2,131.39
4. Step 4: Simplify right side
   3,900.16x = 11,471,013.10
5. Step 5: Solve for x
   x = 11,471,013.10/3,900.16
6. Step 6: Final answer
   x = 2,941.16