Finding the Fourth Proportional to 3,128.28, 4,314.78 and 2,131.98

Step by Step Solution

1. Step 1: Write the proportion equation
   3,128.28 : 4,314.78 = 2,131.98 : x
2. Step 2: Convert to fraction form
   3,128.28/4,314.78 = 2,131.98/x
3. Step 3: Cross multiply
   3,128.28x = 4,314.78 × 2,131.98
4. Step 4: Simplify right side
   3,128.28x = 9,199,024.66
5. Step 5: Solve for x
   x = 9,199,024.66/3,128.28
6. Step 6: Final answer
   x = 2,940.60