Finding the Fourth Proportional to 20,789.43, 31,164.71 and 7,638.27

Step by Step Solution

1. Step 1: Write the proportion equation
   20,789.43 : 31,164.71 = 7,638.27 : x
2. Step 2: Convert to fraction form
   20,789.43/31,164.71 = 7,638.27/x
3. Step 3: Cross multiply
   20,789.43x = 31,164.71 × 7,638.27
4. Step 4: Simplify right side
   20,789.43x = 238,044,431.26
5. Step 5: Solve for x
   x = 238,044,431.26/20,789.43
6. Step 6: Final answer
   x = 11,450.26