Finding the Fourth Proportional to 131.65, 181.31 and 128.82

Step by Step Solution

1. Step 1: Write the proportion equation
   131.65 : 181.31 = 128.82 : x
2. Step 2: Convert to fraction form
   131.65/181.31 = 128.82/x
3. Step 3: Cross multiply
   131.65x = 181.31 × 128.82
4. Step 4: Simplify right side
   131.65x = 23,355.45
5. Step 5: Solve for x
   x = 23,355.45/131.65
6. Step 6: Final answer
   x = 177.41