Finding the Fourth Proportional to 2,638.81, 3,958.17 and 1,078.48

Step by Step Solution

1. Step 1: Write the proportion equation
   2,638.81 : 3,958.17 = 1,078.48 : x
2. Step 2: Convert to fraction form
   2,638.81/3,958.17 = 1,078.48/x
3. Step 3: Cross multiply
   2,638.81x = 3,958.17 × 1,078.48
4. Step 4: Simplify right side
   2,638.81x = 4,268,807.18
5. Step 5: Solve for x
   x = 4,268,807.18/2,638.81
6. Step 6: Final answer
   x = 1,617.70