Finding the Fourth Proportional to 1,405.78, 1,939.98 and 800.08

Step by Step Solution

1. Step 1: Write the proportion equation
   1,405.78 : 1,939.98 = 800.08 : x
2. Step 2: Convert to fraction form
   1,405.78/1,939.98 = 800.08/x
3. Step 3: Cross multiply
   1,405.78x = 1,939.98 × 800.08
4. Step 4: Simplify right side
   1,405.78x = 1,552,139.20
5. Step 5: Solve for x
   x = 1,552,139.20/1,405.78
6. Step 6: Final answer
   x = 1,104.11