Finding the Fourth Proportional to 225.98, 338.69 and 128.56

Step by Step Solution

1. Step 1: Write the proportion equation
   225.98 : 338.69 = 128.56 : x
2. Step 2: Convert to fraction form
   225.98/338.69 = 128.56/x
3. Step 3: Cross multiply
   225.98x = 338.69 × 128.56
4. Step 4: Simplify right side
   225.98x = 43,540.82
5. Step 5: Solve for x
   x = 43,540.82/225.98
6. Step 6: Final answer
   x = 192.68