Finding the Fourth Proportional to 1,146.89, 1,581.17 and 911.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,146.89 : 1,581.17 = 911.61 : x
2. Step 2: Convert to fraction form
   1,146.89/1,581.17 = 911.61/x
3. Step 3: Cross multiply
   1,146.89x = 1,581.17 × 911.61
4. Step 4: Simplify right side
   1,146.89x = 1,441,405.83
5. Step 5: Solve for x
   x = 1,441,405.83/1,146.89
6. Step 6: Final answer
   x = 1,256.80