Finding the Fourth Proportional to 1,085.08, 1,618.48 and 909.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,085.08 : 1,618.48 = 909.72 : x
2. Step 2: Convert to fraction form
   1,085.08/1,618.48 = 909.72/x
3. Step 3: Cross multiply
   1,085.08x = 1,618.48 × 909.72
4. Step 4: Simplify right side
   1,085.08x = 1,472,363.63
5. Step 5: Solve for x
   x = 1,472,363.63/1,085.08
6. Step 6: Final answer
   x = 1,356.92