Finding the Fourth Proportional to 1,392.86, 2,090.13 and 809.00

Step by Step Solution

1. Step 1: Write the proportion equation
   1,392.86 : 2,090.13 = 809.00 : x
2. Step 2: Convert to fraction form
   1,392.86/2,090.13 = 809.00/x
3. Step 3: Cross multiply
   1,392.86x = 2,090.13 × 809.00
4. Step 4: Simplify right side
   1,392.86x = 1,690,904.72
5. Step 5: Solve for x
   x = 1,690,904.72/1,392.86
6. Step 6: Final answer
   x = 1,213.98