Finding the Fourth Proportional to 172.29, 237.83 and 128.69

Step by Step Solution

1. Step 1: Write the proportion equation
   172.29 : 237.83 = 128.69 : x
2. Step 2: Convert to fraction form
   172.29/237.83 = 128.69/x
3. Step 3: Cross multiply
   172.29x = 237.83 × 128.69
4. Step 4: Simplify right side
   172.29x = 30,604.51
5. Step 5: Solve for x
   x = 30,604.51/172.29
6. Step 6: Final answer
   x = 177.63