Finding the Fourth Proportional to 1,648.13, 2,468.09 and 1,128.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,648.13 : 2,468.09 = 1,128.72 : x
2. Step 2: Convert to fraction form
   1,648.13/2,468.09 = 1,128.72/x
3. Step 3: Cross multiply
   1,648.13x = 2,468.09 × 1,128.72
4. Step 4: Simplify right side
   1,648.13x = 2,785,776.90
5. Step 5: Solve for x
   x = 2,785,776.90/1,648.13
6. Step 6: Final answer
   x = 1,690.27