Finding the Fourth Proportional to 1,086.18, 1,628.88 and 355.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,086.18 : 1,628.88 = 355.57 : x
2. Step 2: Convert to fraction form
   1,086.18/1,628.88 = 355.57/x
3. Step 3: Cross multiply
   1,086.18x = 1,628.88 × 355.57
4. Step 4: Simplify right side
   1,086.18x = 579,180.86
5. Step 5: Solve for x
   x = 579,180.86/1,086.18
6. Step 6: Final answer
   x = 533.23