Finding the Fourth Proportional to 1,145.99, 1,581.50 and 648.65

Step by Step Solution

1. Step 1: Write the proportion equation
   1,145.99 : 1,581.50 = 648.65 : x
2. Step 2: Convert to fraction form
   1,145.99/1,581.50 = 648.65/x
3. Step 3: Cross multiply
   1,145.99x = 1,581.50 × 648.65
4. Step 4: Simplify right side
   1,145.99x = 1,025,833.69
5. Step 5: Solve for x
   x = 1,025,833.69/1,145.99
6. Step 6: Final answer
   x = 895.15