Finding the Fourth Proportional to 1,085.89, 1,628.69 and 355.38

Step by Step Solution

1. Step 1: Write the proportion equation
   1,085.89 : 1,628.69 = 355.38 : x
2. Step 2: Convert to fraction form
   1,085.89/1,628.69 = 355.38/x
3. Step 3: Cross multiply
   1,085.89x = 1,628.69 × 355.38
4. Step 4: Simplify right side
   1,085.89x = 578,803.85
5. Step 5: Solve for x
   x = 578,803.85/1,085.89
6. Step 6: Final answer
   x = 533.02