Finding the Fourth Proportional to 1,391.85, 1,920.76 and 802.38

Step by Step Solution

1. Step 1: Write the proportion equation
   1,391.85 : 1,920.76 = 802.38 : x
2. Step 2: Convert to fraction form
   1,391.85/1,920.76 = 802.38/x
3. Step 3: Cross multiply
   1,391.85x = 1,920.76 × 802.38
4. Step 4: Simplify right side
   1,391.85x = 1,541,187.77
5. Step 5: Solve for x
   x = 1,541,187.77/1,391.85
6. Step 6: Final answer
   x = 1,107.30