Finding the Fourth Proportional to 1,081.11, 1,491.89 and 609.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,081.11 : 1,491.89 = 609.06 : x
2. Step 2: Convert to fraction form
   1,081.11/1,491.89 = 609.06/x
3. Step 3: Cross multiply
   1,081.11x = 1,491.89 × 609.06
4. Step 4: Simplify right side
   1,081.11x = 908,647.48
5. Step 5: Solve for x
   x = 908,647.48/1,081.11
6. Step 6: Final answer
   x = 840.48