Finding the Fourth Proportional to 128.06, 176.72 and 72.82

Step by Step Solution

1. Step 1: Write the proportion equation
   128.06 : 176.72 = 72.82 : x
2. Step 2: Convert to fraction form
   128.06/176.72 = 72.82/x
3. Step 3: Cross multiply
   128.06x = 176.72 × 72.82
4. Step 4: Simplify right side
   128.06x = 12,868.75
5. Step 5: Solve for x
   x = 12,868.75/128.06
6. Step 6: Final answer
   x = 100.49