Finding the Fourth Proportional to 86.31, 129.27 and 83.25

Step by Step Solution

1. Step 1: Write the proportion equation
   86.31 : 129.27 = 83.25 : x
2. Step 2: Convert to fraction form
   86.31/129.27 = 83.25/x
3. Step 3: Cross multiply
   86.31x = 129.27 × 83.25
4. Step 4: Simplify right side
   86.31x = 10,761.61
5. Step 5: Solve for x
   x = 10,761.61/86.31
6. Step 6: Final answer
   x = 124.69