Finding the Fourth Proportional to 10,429.76, 15,643.20 and 2,638.12

Step by Step Solution

1. Step 1: Write the proportion equation
   10,429.76 : 15,643.20 = 2,638.12 : x
2. Step 2: Convert to fraction form
   10,429.76/15,643.20 = 2,638.12/x
3. Step 3: Cross multiply
   10,429.76x = 15,643.20 × 2,638.12
4. Step 4: Simplify right side
   10,429.76x = 41,268,638.78
5. Step 5: Solve for x
   x = 41,268,638.78/10,429.76
6. Step 6: Final answer
   x = 3,956.82