Finding the Fourth Proportional to 89.69, 123.08 and 81.48

Step by Step Solution

1. Step 1: Write the proportion equation
   89.69 : 123.08 = 81.48 : x
2. Step 2: Convert to fraction form
   89.69/123.08 = 81.48/x
3. Step 3: Cross multiply
   89.69x = 123.08 × 81.48
4. Step 4: Simplify right side
   89.69x = 10,028.56
5. Step 5: Solve for x
   x = 10,028.56/89.69
6. Step 6: Final answer
   x = 111.81