Finding the Fourth Proportional to 559.42, 772.56 and 498.31

Step by Step Solution

1. Step 1: Write the proportion equation
   559.42 : 772.56 = 498.31 : x
2. Step 2: Convert to fraction form
   559.42/772.56 = 498.31/x
3. Step 3: Cross multiply
   559.42x = 772.56 × 498.31
4. Step 4: Simplify right side
   559.42x = 384,974.37
5. Step 5: Solve for x
   x = 384,974.37/559.42
6. Step 6: Final answer
   x = 688.17