Finding the Fourth Proportional to 1,145.75, 1,581.22 and 648.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,145.75 : 1,581.22 = 648.30 : x
2. Step 2: Convert to fraction form
   1,145.75/1,581.22 = 648.30/x
3. Step 3: Cross multiply
   1,145.75x = 1,581.22 × 648.30
4. Step 4: Simplify right side
   1,145.75x = 1,025,111.67
5. Step 5: Solve for x
   x = 1,025,111.67/1,145.75
6. Step 6: Final answer
   x = 894.71