Finding the Fourth Proportional to 2,171.48, 3,251.94 and 1,128.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,171.48 : 3,251.94 = 1,128.20 : x
2. Step 2: Convert to fraction form
   2,171.48/3,251.94 = 1,128.20/x
3. Step 3: Cross multiply
   2,171.48x = 3,251.94 × 1,128.20
4. Step 4: Simplify right side
   2,171.48x = 3,668,838.71
5. Step 5: Solve for x
   x = 3,668,838.71/2,171.48
6. Step 6: Final answer
   x = 1,689.56