Finding the Fourth Proportional to 89.16, 122.91 and 86.83

Step by Step Solution

1. Step 1: Write the proportion equation
   89.16 : 122.91 = 86.83 : x
2. Step 2: Convert to fraction form
   89.16/122.91 = 86.83/x
3. Step 3: Cross multiply
   89.16x = 122.91 × 86.83
4. Step 4: Simplify right side
   89.16x = 10,672.28
5. Step 5: Solve for x
   x = 10,672.28/89.16
6. Step 6: Final answer
   x = 119.70