Finding the Fourth Proportional to 1,388.16, 1,916.04 and 798.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.16 : 1,916.04 = 798.88 : x
2. Step 2: Convert to fraction form
   1,388.16/1,916.04 = 798.88/x
3. Step 3: Cross multiply
   1,388.16x = 1,916.04 × 798.88
4. Step 4: Simplify right side
   1,388.16x = 1,530,686.04
5. Step 5: Solve for x
   x = 1,530,686.04/1,388.16
6. Step 6: Final answer
   x = 1,102.67