Finding the Fourth Proportional to 2,736.78, 4,105.20 and 789

Step by Step Solution

1. Step 1: Write the proportion equation
   2,736.78 : 4,105.20 = 789 : x
2. Step 2: Convert to fraction form
   2,736.78/4,105.20 = 789/x
3. Step 3: Cross multiply
   2,736.78x = 4,105.20 × 789
4. Step 4: Simplify right side
   2,736.78x = 3,239,002.80
5. Step 5: Solve for x
   x = 3,239,002.80/2,736.78
6. Step 6: Final answer
   x = 1,183.51