Finding the Fourth Proportional to 1,389.48, 1,917.24 and 800.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.48 : 1,917.24 = 800.28 : x
2. Step 2: Convert to fraction form
   1,389.48/1,917.24 = 800.28/x
3. Step 3: Cross multiply
   1,389.48x = 1,917.24 × 800.28
4. Step 4: Simplify right side
   1,389.48x = 1,534,328.83
5. Step 5: Solve for x
   x = 1,534,328.83/1,389.48
6. Step 6: Final answer
   x = 1,104.25