Finding the Fourth Proportional to 1,391.01, 1,919.31 and 801.39

Step by Step Solution

1. Step 1: Write the proportion equation
   1,391.01 : 1,919.31 = 801.39 : x
2. Step 2: Convert to fraction form
   1,391.01/1,919.31 = 801.39/x
3. Step 3: Cross multiply
   1,391.01x = 1,919.31 × 801.39
4. Step 4: Simplify right side
   1,391.01x = 1,538,115.84
5. Step 5: Solve for x
   x = 1,538,115.84/1,391.01
6. Step 6: Final answer
   x = 1,105.75