Finding the Fourth Proportional to 1,388.72, 1,916.38 and 799.36

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.72 : 1,916.38 = 799.36 : x
2. Step 2: Convert to fraction form
   1,388.72/1,916.38 = 799.36/x
3. Step 3: Cross multiply
   1,388.72x = 1,916.38 × 799.36
4. Step 4: Simplify right side
   1,388.72x = 1,531,873.73
5. Step 5: Solve for x
   x = 1,531,873.73/1,388.72
6. Step 6: Final answer
   x = 1,103.08