Finding the Fourth Proportional to 1,085.86, 1,628.61 and 355.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,085.86 : 1,628.61 = 355.42 : x
2. Step 2: Convert to fraction form
   1,085.86/1,628.61 = 355.42/x
3. Step 3: Cross multiply
   1,085.86x = 1,628.61 × 355.42
4. Step 4: Simplify right side
   1,085.86x = 578,840.57
5. Step 5: Solve for x
   x = 578,840.57/1,085.86
6. Step 6: Final answer
   x = 533.07