Finding the Fourth Proportional to 1,128.48, 1,693.17 and 479.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,128.48 : 1,693.17 = 479.31 : x
2. Step 2: Convert to fraction form
   1,128.48/1,693.17 = 479.31/x
3. Step 3: Cross multiply
   1,128.48x = 1,693.17 × 479.31
4. Step 4: Simplify right side
   1,128.48x = 811,553.31
5. Step 5: Solve for x
   x = 811,553.31/1,128.48
6. Step 6: Final answer
   x = 719.16