Finding the Fourth Proportional to 1,398.83, 1,930.61 and 809.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.83 : 1,930.61 = 809.69 : x
2. Step 2: Convert to fraction form
   1,398.83/1,930.61 = 809.69/x
3. Step 3: Cross multiply
   1,398.83x = 1,930.61 × 809.69
4. Step 4: Simplify right side
   1,398.83x = 1,563,202.46
5. Step 5: Solve for x
   x = 1,563,202.46/1,398.83
6. Step 6: Final answer
   x = 1,117.51