Finding the Fourth Proportional to 265.82, 398.59 and 128.59

Step by Step Solution

1. Step 1: Write the proportion equation
   265.82 : 398.59 = 128.59 : x
2. Step 2: Convert to fraction form
   265.82/398.59 = 128.59/x
3. Step 3: Cross multiply
   265.82x = 398.59 × 128.59
4. Step 4: Simplify right side
   265.82x = 51,253.37
5. Step 5: Solve for x
   x = 51,253.37/265.82
6. Step 6: Final answer
   x = 192.82