Finding the Fourth Proportional to 3,175.24, 4,378.98 and 2,128.72

Step by Step Solution

1. Step 1: Write the proportion equation
   3,175.24 : 4,378.98 = 2,128.72 : x
2. Step 2: Convert to fraction form
   3,175.24/4,378.98 = 2,128.72/x
3. Step 3: Cross multiply
   3,175.24x = 4,378.98 × 2,128.72
4. Step 4: Simplify right side
   3,175.24x = 9,321,622.31
5. Step 5: Solve for x
   x = 9,321,622.31/3,175.24
6. Step 6: Final answer
   x = 2,935.72