Finding the Fourth Proportional to 1,574.78, 2,173.35 and 911.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,574.78 : 2,173.35 = 911.61 : x
2. Step 2: Convert to fraction form
   1,574.78/2,173.35 = 911.61/x
3. Step 3: Cross multiply
   1,574.78x = 2,173.35 × 911.61
4. Step 4: Simplify right side
   1,574.78x = 1,981,247.59
5. Step 5: Solve for x
   x = 1,981,247.59/1,574.78
6. Step 6: Final answer
   x = 1,258.11