Finding the Fourth Proportional to 86.17, 129.27 and 42.82

Step by Step Solution

1. Step 1: Write the proportion equation
   86.17 : 129.27 = 42.82 : x
2. Step 2: Convert to fraction form
   86.17/129.27 = 42.82/x
3. Step 3: Cross multiply
   86.17x = 129.27 × 42.82
4. Step 4: Simplify right side
   86.17x = 5,535.34
5. Step 5: Solve for x
   x = 5,535.34/86.17
6. Step 6: Final answer
   x = 64.24