Finding the Fourth Proportional to 19,222.56, 28,845 and 8,128.56

Step by Step Solution

1. Step 1: Write the proportion equation
   19,222.56 : 28,845 = 8,128.56 : x
2. Step 2: Convert to fraction form
   19,222.56/28,845 = 8,128.56/x
3. Step 3: Cross multiply
   19,222.56x = 28,845 × 8,128.56
4. Step 4: Simplify right side
   19,222.56x = 234,468,313.20
5. Step 5: Solve for x
   x = 234,468,313.20/19,222.56
6. Step 6: Final answer
   x = 12,197.56