Finding the Fourth Proportional to 2,085.53, 3,128.31 and 698.87

Step by Step Solution

1. Step 1: Write the proportion equation
   2,085.53 : 3,128.31 = 698.87 : x
2. Step 2: Convert to fraction form
   2,085.53/3,128.31 = 698.87/x
3. Step 3: Cross multiply
   2,085.53x = 3,128.31 × 698.87
4. Step 4: Simplify right side
   2,085.53x = 2,186,289.83
5. Step 5: Solve for x
   x = 2,186,289.83/2,085.53
6. Step 6: Final answer
   x = 1,048.32