Finding the Fourth Proportional to 2,638.06, 3,957.80 and 789.18

Step by Step Solution

1. Step 1: Write the proportion equation
   2,638.06 : 3,957.80 = 789.18 : x
2. Step 2: Convert to fraction form
   2,638.06/3,957.80 = 789.18/x
3. Step 3: Cross multiply
   2,638.06x = 3,957.80 × 789.18
4. Step 4: Simplify right side
   2,638.06x = 3,123,416.60
5. Step 5: Solve for x
   x = 3,123,416.60/2,638.06
6. Step 6: Final answer
   x = 1,183.98