Finding the Fourth Proportional to 1,391.52, 1,920.84 and 802.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,391.52 : 1,920.84 = 802.56 : x
2. Step 2: Convert to fraction form
   1,391.52/1,920.84 = 802.56/x
3. Step 3: Cross multiply
   1,391.52x = 1,920.84 × 802.56
4. Step 4: Simplify right side
   1,391.52x = 1,541,589.35
5. Step 5: Solve for x
   x = 1,541,589.35/1,391.52
6. Step 6: Final answer
   x = 1,107.85