Finding the Fourth Proportional to 1,391.99, 1,920.56 and 802.49

Step by Step Solution

1. Step 1: Write the proportion equation
   1,391.99 : 1,920.56 = 802.49 : x
2. Step 2: Convert to fraction form
   1,391.99/1,920.56 = 802.49/x
3. Step 3: Cross multiply
   1,391.99x = 1,920.56 × 802.49
4. Step 4: Simplify right side
   1,391.99x = 1,541,216.58
5. Step 5: Solve for x
   x = 1,541,216.58/1,391.99
6. Step 6: Final answer
   x = 1,107.21