Finding the Fourth Proportional to 311.34, 466.89 and 128.69

Step by Step Solution

1. Step 1: Write the proportion equation
   311.34 : 466.89 = 128.69 : x
2. Step 2: Convert to fraction form
   311.34/466.89 = 128.69/x
3. Step 3: Cross multiply
   311.34x = 466.89 × 128.69
4. Step 4: Simplify right side
   311.34x = 60,081.74
5. Step 5: Solve for x
   x = 60,081.74/311.34
6. Step 6: Final answer
   x = 192.98