Finding the Fourth Proportional to 1,399.44, 1,930.86 and 809.94

Step by Step Solution

1. Step 1: Write the proportion equation
   1,399.44 : 1,930.86 = 809.94 : x
2. Step 2: Convert to fraction form
   1,399.44/1,930.86 = 809.94/x
3. Step 3: Cross multiply
   1,399.44x = 1,930.86 × 809.94
4. Step 4: Simplify right side
   1,399.44x = 1,563,880.75
5. Step 5: Solve for x
   x = 1,563,880.75/1,399.44
6. Step 6: Final answer
   x = 1,117.50