Finding the Fourth Proportional to 1,145.95, 1,581.42 and 648.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,145.95 : 1,581.42 = 648.61 : x
2. Step 2: Convert to fraction form
   1,145.95/1,581.42 = 648.61/x
3. Step 3: Cross multiply
   1,145.95x = 1,581.42 × 648.61
4. Step 4: Simplify right side
   1,145.95x = 1,025,724.83
5. Step 5: Solve for x
   x = 1,025,724.83/1,145.95
6. Step 6: Final answer
   x = 895.09