Finding the Fourth Proportional to 1,081.85, 1,492.16 and 661.86

Step by Step Solution

1. Step 1: Write the proportion equation
   1,081.85 : 1,492.16 = 661.86 : x
2. Step 2: Convert to fraction form
   1,081.85/1,492.16 = 661.86/x
3. Step 3: Cross multiply
   1,081.85x = 1,492.16 × 661.86
4. Step 4: Simplify right side
   1,081.85x = 987,597.71
5. Step 5: Solve for x
   x = 987,597.71/1,081.85
6. Step 6: Final answer
   x = 912.88