Finding the Fourth Proportional to 2,638.67, 3,957.33 and 789.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,638.67 : 3,957.33 = 789.31 : x
2. Step 2: Convert to fraction form
   2,638.67/3,957.33 = 789.31/x
3. Step 3: Cross multiply
   2,638.67x = 3,957.33 × 789.31
4. Step 4: Simplify right side
   2,638.67x = 3,123,560.14
5. Step 5: Solve for x
   x = 3,123,560.14/2,638.67
6. Step 6: Final answer
   x = 1,183.76