Finding the Fourth Proportional to 1,398.60, 1,930.32 and 809.46

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.60 : 1,930.32 = 809.46 : x
2. Step 2: Convert to fraction form
   1,398.60/1,930.32 = 809.46/x
3. Step 3: Cross multiply
   1,398.60x = 1,930.32 × 809.46
4. Step 4: Simplify right side
   1,398.60x = 1,562,516.83
5. Step 5: Solve for x
   x = 1,562,516.83/1,398.60
6. Step 6: Final answer
   x = 1,117.20