Finding the Fourth Proportional to 1,391.32, 1,920.22 and 802.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,391.32 : 1,920.22 = 802.20 : x
2. Step 2: Convert to fraction form
   1,391.32/1,920.22 = 802.20/x
3. Step 3: Cross multiply
   1,391.32x = 1,920.22 × 802.20
4. Step 4: Simplify right side
   1,391.32x = 1,540,400.48
5. Step 5: Solve for x
   x = 1,540,400.48/1,391.32
6. Step 6: Final answer
   x = 1,107.15