Finding the Fourth Proportional to 3,900.28, 5,382.37 and 2,131.88

Step by Step Solution

1. Step 1: Write the proportion equation
   3,900.28 : 5,382.37 = 2,131.88 : x
2. Step 2: Convert to fraction form
   3,900.28/5,382.37 = 2,131.88/x
3. Step 3: Cross multiply
   3,900.28x = 5,382.37 × 2,131.88
4. Step 4: Simplify right side
   3,900.28x = 11,474,556.30
5. Step 5: Solve for x
   x = 11,474,556.30/3,900.28
6. Step 6: Final answer
   x = 2,941.99