Finding the Fourth Proportional to 86.37, 129.72 and 83.97

Step by Step Solution

1. Step 1: Write the proportion equation
   86.37 : 129.72 = 83.97 : x
2. Step 2: Convert to fraction form
   86.37/129.72 = 83.97/x
3. Step 3: Cross multiply
   86.37x = 129.72 × 83.97
4. Step 4: Simplify right side
   86.37x = 10,892.43
5. Step 5: Solve for x
   x = 10,892.43/86.37
6. Step 6: Final answer
   x = 126.12