Finding the Fourth Proportional to 1,389.32, 1,917.46 and 800.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.32 : 1,917.46 = 800.20 : x
2. Step 2: Convert to fraction form
   1,389.32/1,917.46 = 800.20/x
3. Step 3: Cross multiply
   1,389.32x = 1,917.46 × 800.20
4. Step 4: Simplify right side
   1,389.32x = 1,534,351.49
5. Step 5: Solve for x
   x = 1,534,351.49/1,389.32
6. Step 6: Final answer
   x = 1,104.39