Finding the Fourth Proportional to 1,145.92, 1,580.79 and 725.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,145.92 : 1,580.79 = 725.57 : x
2. Step 2: Convert to fraction form
   1,145.92/1,580.79 = 725.57/x
3. Step 3: Cross multiply
   1,145.92x = 1,580.79 × 725.57
4. Step 4: Simplify right side
   1,145.92x = 1,146,973.80
5. Step 5: Solve for x
   x = 1,146,973.80/1,145.92
6. Step 6: Final answer
   x = 1,000.92