Finding the Fourth Proportional to 1,399.24, 1,930.92 and 809.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,399.24 : 1,930.92 = 809.76 : x
2. Step 2: Convert to fraction form
   1,399.24/1,930.92 = 809.76/x
3. Step 3: Cross multiply
   1,399.24x = 1,930.92 × 809.76
4. Step 4: Simplify right side
   1,399.24x = 1,563,581.78
5. Step 5: Solve for x
   x = 1,563,581.78/1,399.24
6. Step 6: Final answer
   x = 1,117.45