Finding the Fourth Proportional to 20,193.89, 27,870.56 and 12,128.09

Step by Step Solution

1. Step 1: Write the proportion equation
   20,193.89 : 27,870.56 = 12,128.09 : x
2. Step 2: Convert to fraction form
   20,193.89/27,870.56 = 12,128.09/x
3. Step 3: Cross multiply
   20,193.89x = 27,870.56 × 12,128.09
4. Step 4: Simplify right side
   20,193.89x = 338,016,660.03
5. Step 5: Solve for x
   x = 338,016,660.03/20,193.89
6. Step 6: Final answer
   x = 16,738.56