Finding the Fourth Proportional to 1,391.56, 1,920.41 and 802.09

Step by Step Solution

1. Step 1: Write the proportion equation
   1,391.56 : 1,920.41 = 802.09 : x
2. Step 2: Convert to fraction form
   1,391.56/1,920.41 = 802.09/x
3. Step 3: Cross multiply
   1,391.56x = 1,920.41 × 802.09
4. Step 4: Simplify right side
   1,391.56x = 1,540,341.66
5. Step 5: Solve for x
   x = 1,540,341.66/1,391.56
6. Step 6: Final answer
   x = 1,106.92