Finding the Fourth Proportional to 2,638.39, 3,958.15 and 789.67

Step by Step Solution

1. Step 1: Write the proportion equation
   2,638.39 : 3,958.15 = 789.67 : x
2. Step 2: Convert to fraction form
   2,638.39/3,958.15 = 789.67/x
3. Step 3: Cross multiply
   2,638.39x = 3,958.15 × 789.67
4. Step 4: Simplify right side
   2,638.39x = 3,125,632.31
5. Step 5: Solve for x
   x = 3,125,632.31/2,638.39
6. Step 6: Final answer
   x = 1,184.67