Finding the Fourth Proportional to 1,439.12, 1,986.23 and 809.93

Step by Step Solution

1. Step 1: Write the proportion equation
   1,439.12 : 1,986.23 = 809.93 : x
2. Step 2: Convert to fraction form
   1,439.12/1,986.23 = 809.93/x
3. Step 3: Cross multiply
   1,439.12x = 1,986.23 × 809.93
4. Step 4: Simplify right side
   1,439.12x = 1,608,703.21
5. Step 5: Solve for x
   x = 1,608,703.21/1,439.12
6. Step 6: Final answer
   x = 1,117.84