Finding the Fourth Proportional to 2,085.52, 3,128.10 and 698.80

Step by Step Solution

1. Step 1: Write the proportion equation
   2,085.52 : 3,128.10 = 698.80 : x
2. Step 2: Convert to fraction form
   2,085.52/3,128.10 = 698.80/x
3. Step 3: Cross multiply
   2,085.52x = 3,128.10 × 698.80
4. Step 4: Simplify right side
   2,085.52x = 2,185,916.28
5. Step 5: Solve for x
   x = 2,185,916.28/2,085.52
6. Step 6: Final answer
   x = 1,048.14