Finding the Fourth Proportional to 1,145.76, 1,581.12 and 648.39

Step by Step Solution

1. Step 1: Write the proportion equation
   1,145.76 : 1,581.12 = 648.39 : x
2. Step 2: Convert to fraction form
   1,145.76/1,581.12 = 648.39/x
3. Step 3: Cross multiply
   1,145.76x = 1,581.12 × 648.39
4. Step 4: Simplify right side
   1,145.76x = 1,025,182.40
5. Step 5: Solve for x
   x = 1,025,182.40/1,145.76
6. Step 6: Final answer
   x = 894.76