Finding the Fourth Proportional to 89.31, 123.30 and 86.49

Step by Step Solution

1. Step 1: Write the proportion equation
   89.31 : 123.30 = 86.49 : x
2. Step 2: Convert to fraction form
   89.31/123.30 = 86.49/x
3. Step 3: Cross multiply
   89.31x = 123.30 × 86.49
4. Step 4: Simplify right side
   89.31x = 10,664.22
5. Step 5: Solve for x
   x = 10,664.22/89.31
6. Step 6: Final answer
   x = 119.41