Finding the Fourth Proportional to 1,399.01, 1,930.64 and 809.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,399.01 : 1,930.64 = 809.55 : x
2. Step 2: Convert to fraction form
   1,399.01/1,930.64 = 809.55/x
3. Step 3: Cross multiply
   1,399.01x = 1,930.64 × 809.55
4. Step 4: Simplify right side
   1,399.01x = 1,562,945.56
5. Step 5: Solve for x
   x = 1,562,945.56/1,399.01
6. Step 6: Final answer
   x = 1,117.18