Finding the Fourth Proportional to 1,085.60, 1,628.71 and 355.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,085.60 : 1,628.71 = 355.69 : x
2. Step 2: Convert to fraction form
   1,085.60/1,628.71 = 355.69/x
3. Step 3: Cross multiply
   1,085.60x = 1,628.71 × 355.69
4. Step 4: Simplify right side
   1,085.60x = 579,317.01
5. Step 5: Solve for x
   x = 579,317.01/1,085.60
6. Step 6: Final answer
   x = 533.64