Finding the Fourth Proportional to 88.24, 131.72 and 81.89

Step by Step Solution

1. Step 1: Write the proportion equation
   88.24 : 131.72 = 81.89 : x
2. Step 2: Convert to fraction form
   88.24/131.72 = 81.89/x
3. Step 3: Cross multiply
   88.24x = 131.72 × 81.89
4. Step 4: Simplify right side
   88.24x = 10,786.55
5. Step 5: Solve for x
   x = 10,786.55/88.24
6. Step 6: Final answer
   x = 122.25