Finding the Fourth Proportional to 1,012.48, 1,519.31 and 396.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,012.48 : 1,519.31 = 396.61 : x
2. Step 2: Convert to fraction form
   1,012.48/1,519.31 = 396.61/x
3. Step 3: Cross multiply
   1,012.48x = 1,519.31 × 396.61
4. Step 4: Simplify right side
   1,012.48x = 602,573.54
5. Step 5: Solve for x
   x = 602,573.54/1,012.48
6. Step 6: Final answer
   x = 595.15