Finding the Fourth Proportional to 429.02, 642.82 and 168.72

Step by Step Solution

1. Step 1: Write the proportion equation
   429.02 : 642.82 = 168.72 : x
2. Step 2: Convert to fraction form
   429.02/642.82 = 168.72/x
3. Step 3: Cross multiply
   429.02x = 642.82 × 168.72
4. Step 4: Simplify right side
   429.02x = 108,456.59
5. Step 5: Solve for x
   x = 108,456.59/429.02
6. Step 6: Final answer
   x = 252.80