Finding the Fourth Proportional to 20,790.43, 31,166.20 and 7,639.27

Step by Step Solution

1. Step 1: Write the proportion equation
   20,790.43 : 31,166.20 = 7,639.27 : x
2. Step 2: Convert to fraction form
   20,790.43/31,166.20 = 7,639.27/x
3. Step 3: Cross multiply
   20,790.43x = 31,166.20 × 7,639.27
4. Step 4: Simplify right side
   20,790.43x = 238,087,016.67
5. Step 5: Solve for x
   x = 238,087,016.67/20,790.43
6. Step 6: Final answer
   x = 11,451.76