Finding the Fourth Proportional to 1,610.79, 2,415.20 and 685.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,610.79 : 2,415.20 = 685.82 : x
2. Step 2: Convert to fraction form
   1,610.79/2,415.20 = 685.82/x
3. Step 3: Cross multiply
   1,610.79x = 2,415.20 × 685.82
4. Step 4: Simplify right side
   1,610.79x = 1,656,392.46
5. Step 5: Solve for x
   x = 1,656,392.46/1,610.79
6. Step 6: Final answer
   x = 1,028.31