Finding the Fourth Proportional to 2,638.31, 3,956.30 and 1,405.46

Step by Step Solution

1. Step 1: Write the proportion equation
   2,638.31 : 3,956.30 = 1,405.46 : x
2. Step 2: Convert to fraction form
   2,638.31/3,956.30 = 1,405.46/x
3. Step 3: Cross multiply
   2,638.31x = 3,956.30 × 1,405.46
4. Step 4: Simplify right side
   2,638.31x = 5,560,399.86
5. Step 5: Solve for x
   x = 5,560,399.86/2,638.31
6. Step 6: Final answer
   x = 2,107.56