Finding the Fourth Proportional to 1,388.43, 1,916.36 and 799.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.43 : 1,916.36 = 799.31 : x
2. Step 2: Convert to fraction form
   1,388.43/1,916.36 = 799.31/x
3. Step 3: Cross multiply
   1,388.43x = 1,916.36 × 799.31
4. Step 4: Simplify right side
   1,388.43x = 1,531,765.71
5. Step 5: Solve for x
   x = 1,531,765.71/1,388.43
6. Step 6: Final answer
   x = 1,103.24