Finding the Fourth Proportional to 1,145.49, 1,580.75 and 648.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,145.49 : 1,580.75 = 648.12 : x
2. Step 2: Convert to fraction form
   1,145.49/1,580.75 = 648.12/x
3. Step 3: Cross multiply
   1,145.49x = 1,580.75 × 648.12
4. Step 4: Simplify right side
   1,145.49x = 1,024,512.45
5. Step 5: Solve for x
   x = 1,024,512.45/1,145.49
6. Step 6: Final answer
   x = 894.39