Finding the Fourth Proportional to 1,389.59, 1,917.22 and 800.11

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.59 : 1,917.22 = 800.11 : x
2. Step 2: Convert to fraction form
   1,389.59/1,917.22 = 800.11/x
3. Step 3: Cross multiply
   1,389.59x = 1,917.22 × 800.11
4. Step 4: Simplify right side
   1,389.59x = 1,533,973.31
5. Step 5: Solve for x
   x = 1,533,973.31/1,389.59
6. Step 6: Final answer
   x = 1,103.91