Finding the Fourth Proportional to 1,056.49, 1,583.31 and 439.47

Step by Step Solution

1. Step 1: Write the proportion equation
   1,056.49 : 1,583.31 = 439.47 : x
2. Step 2: Convert to fraction form
   1,056.49/1,583.31 = 439.47/x
3. Step 3: Cross multiply
   1,056.49x = 1,583.31 × 439.47
4. Step 4: Simplify right side
   1,056.49x = 695,818.89
5. Step 5: Solve for x
   x = 695,818.89/1,056.49
6. Step 6: Final answer
   x = 658.62