Finding the Fourth Proportional to 1,725.32, 2,589.20 and 685.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,725.32 : 2,589.20 = 685.55 : x
2. Step 2: Convert to fraction form
   1,725.32/2,589.20 = 685.55/x
3. Step 3: Cross multiply
   1,725.32x = 2,589.20 × 685.55
4. Step 4: Simplify right side
   1,725.32x = 1,775,009.69
5. Step 5: Solve for x
   x = 1,775,009.69/1,725.32
6. Step 6: Final answer
   x = 1,028.80