Finding the Fourth Proportional to 2,638.36, 3,956.37 and 1,405.54

Step by Step Solution

1. Step 1: Write the proportion equation
   2,638.36 : 3,956.37 = 1,405.54 : x
2. Step 2: Convert to fraction form
   2,638.36/3,956.37 = 1,405.54/x
3. Step 3: Cross multiply
   2,638.36x = 3,956.37 × 1,405.54
4. Step 4: Simplify right side
   2,638.36x = 5,560,836.29
5. Step 5: Solve for x
   x = 5,560,836.29/2,638.36
6. Step 6: Final answer
   x = 2,107.69