Finding the Fourth Proportional to 1,298.27, 1,789.75 and 800.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,298.27 : 1,789.75 = 800.57 : x
2. Step 2: Convert to fraction form
   1,298.27/1,789.75 = 800.57/x
3. Step 3: Cross multiply
   1,298.27x = 1,789.75 × 800.57
4. Step 4: Simplify right side
   1,298.27x = 1,432,816.15
5. Step 5: Solve for x
   x = 1,432,816.15/1,298.27
6. Step 6: Final answer
   x = 1,103.64