Finding the Fourth Proportional to 1,145.30, 1,580.56 and 648

Step by Step Solution

1. Step 1: Write the proportion equation
   1,145.30 : 1,580.56 = 648 : x
2. Step 2: Convert to fraction form
   1,145.30/1,580.56 = 648/x
3. Step 3: Cross multiply
   1,145.30x = 1,580.56 × 648
4. Step 4: Simplify right side
   1,145.30x = 1,024,202.88
5. Step 5: Solve for x
   x = 1,024,202.88/1,145.30
6. Step 6: Final answer
   x = 894.27