Finding the Fourth Proportional to 1,389.98, 1,917.96 and 800.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.98 : 1,917.96 = 800.42 : x
2. Step 2: Convert to fraction form
   1,389.98/1,917.96 = 800.42/x
3. Step 3: Cross multiply
   1,389.98x = 1,917.96 × 800.42
4. Step 4: Simplify right side
   1,389.98x = 1,535,173.54
5. Step 5: Solve for x
   x = 1,535,173.54/1,389.98
6. Step 6: Final answer
   x = 1,104.46