Finding the Fourth Proportional to 1,439.07, 1,985.46 and 809.49

Step by Step Solution

1. Step 1: Write the proportion equation
   1,439.07 : 1,985.46 = 809.49 : x
2. Step 2: Convert to fraction form
   1,439.07/1,985.46 = 809.49/x
3. Step 3: Cross multiply
   1,439.07x = 1,985.46 × 809.49
4. Step 4: Simplify right side
   1,439.07x = 1,607,218.98
5. Step 5: Solve for x
   x = 1,607,218.98/1,439.07
6. Step 6: Final answer
   x = 1,116.85