Finding the Fourth Proportional to 1,085.39, 1,628.18 and 392.33

Step by Step Solution

1. Step 1: Write the proportion equation
   1,085.39 : 1,628.18 = 392.33 : x
2. Step 2: Convert to fraction form
   1,085.39/1,628.18 = 392.33/x
3. Step 3: Cross multiply
   1,085.39x = 1,628.18 × 392.33
4. Step 4: Simplify right side
   1,085.39x = 638,783.86
5. Step 5: Solve for x
   x = 638,783.86/1,085.39
6. Step 6: Final answer
   x = 588.53