Finding the Fourth Proportional to 1,388.50, 1,916.15 and 799.07

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.50 : 1,916.15 = 799.07 : x
2. Step 2: Convert to fraction form
   1,388.50/1,916.15 = 799.07/x
3. Step 3: Cross multiply
   1,388.50x = 1,916.15 × 799.07
4. Step 4: Simplify right side
   1,388.50x = 1,531,124.40
5. Step 5: Solve for x
   x = 1,531,124.40/1,388.50
6. Step 6: Final answer
   x = 1,102.72