Finding the Fourth Proportional to 1,096.47, 1,644.71 and 438.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,096.47 : 1,644.71 = 438.31 : x
2. Step 2: Convert to fraction form
   1,096.47/1,644.71 = 438.31/x
3. Step 3: Cross multiply
   1,096.47x = 1,644.71 × 438.31
4. Step 4: Simplify right side
   1,096.47x = 720,892.70
5. Step 5: Solve for x
   x = 720,892.70/1,096.47
6. Step 6: Final answer
   x = 657.47