Finding the Fourth Proportional to 825.83, 1,139.61 and 494.09

Step by Step Solution

1. Step 1: Write the proportion equation
   825.83 : 1,139.61 = 494.09 : x
2. Step 2: Convert to fraction form
   825.83/1,139.61 = 494.09/x
3. Step 3: Cross multiply
   825.83x = 1,139.61 × 494.09
4. Step 4: Simplify right side
   825.83x = 563,064.21
5. Step 5: Solve for x
   x = 563,064.21/825.83
6. Step 6: Final answer
   x = 681.82