Finding the Fourth Proportional to 825.61, 1,139.31 and 494.22

Step by Step Solution

1. Step 1: Write the proportion equation
   825.61 : 1,139.31 = 494.22 : x
2. Step 2: Convert to fraction form
   825.61/1,139.31 = 494.22/x
3. Step 3: Cross multiply
   825.61x = 1,139.31 × 494.22
4. Step 4: Simplify right side
   825.61x = 563,061.62
5. Step 5: Solve for x
   x = 563,061.62/825.61
6. Step 6: Final answer
   x = 682.00