Finding the Fourth Proportional to 1,388.98, 1,916.73 and 799.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.98 : 1,916.73 = 799.60 : x
2. Step 2: Convert to fraction form
   1,388.98/1,916.73 = 799.60/x
3. Step 3: Cross multiply
   1,388.98x = 1,916.73 × 799.60
4. Step 4: Simplify right side
   1,388.98x = 1,532,617.31
5. Step 5: Solve for x
   x = 1,532,617.31/1,388.98
6. Step 6: Final answer
   x = 1,103.41