Finding the Fourth Proportional to 1,391.02, 1,919.77 and 801.67

Step by Step Solution

1. Step 1: Write the proportion equation
   1,391.02 : 1,919.77 = 801.67 : x
2. Step 2: Convert to fraction form
   1,391.02/1,919.77 = 801.67/x
3. Step 3: Cross multiply
   1,391.02x = 1,919.77 × 801.67
4. Step 4: Simplify right side
   1,391.02x = 1,539,022.02
5. Step 5: Solve for x
   x = 1,539,022.02/1,391.02
6. Step 6: Final answer
   x = 1,106.40