Finding the Fourth Proportional to 3,128.47, 4,313.83 and 2,131.75

Step by Step Solution

1. Step 1: Write the proportion equation
   3,128.47 : 4,313.83 = 2,131.75 : x
2. Step 2: Convert to fraction form
   3,128.47/4,313.83 = 2,131.75/x
3. Step 3: Cross multiply
   3,128.47x = 4,313.83 × 2,131.75
4. Step 4: Simplify right side
   3,128.47x = 9,196,007.10
5. Step 5: Solve for x
   x = 9,196,007.10/3,128.47
6. Step 6: Final answer
   x = 2,939.46