Finding the Fourth Proportional to 1,391.90, 1,921.24 and 802.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,391.90 : 1,921.24 = 802.82 : x
2. Step 2: Convert to fraction form
   1,391.90/1,921.24 = 802.82/x
3. Step 3: Cross multiply
   1,391.90x = 1,921.24 × 802.82
4. Step 4: Simplify right side
   1,391.90x = 1,542,409.90
5. Step 5: Solve for x
   x = 1,542,409.90/1,391.90
6. Step 6: Final answer
   x = 1,108.13