Finding the Fourth Proportional to 89.38, 123.36 and 86.55

Step by Step Solution

1. Step 1: Write the proportion equation
   89.38 : 123.36 = 86.55 : x
2. Step 2: Convert to fraction form
   89.38/123.36 = 86.55/x
3. Step 3: Cross multiply
   89.38x = 123.36 × 86.55
4. Step 4: Simplify right side
   89.38x = 10,676.02
5. Step 5: Solve for x
   x = 10,676.02/89.38
6. Step 6: Final answer
   x = 119.44