Finding the Fourth Proportional to 1,659.42, 2,488.59 and 685.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,659.42 : 2,488.59 = 685.80 : x
2. Step 2: Convert to fraction form
   1,659.42/2,488.59 = 685.80/x
3. Step 3: Cross multiply
   1,659.42x = 2,488.59 × 685.80
4. Step 4: Simplify right side
   1,659.42x = 1,706,675.02
5. Step 5: Solve for x
   x = 1,706,675.02/1,659.42
6. Step 6: Final answer
   x = 1,028.48