Finding the Fourth Proportional to 86.72, 129.82 and 57.82

Step by Step Solution

1. Step 1: Write the proportion equation
   86.72 : 129.82 = 57.82 : x
2. Step 2: Convert to fraction form
   86.72/129.82 = 57.82/x
3. Step 3: Cross multiply
   86.72x = 129.82 × 57.82
4. Step 4: Simplify right side
   86.72x = 7,506.19
5. Step 5: Solve for x
   x = 7,506.19/86.72
6. Step 6: Final answer
   x = 86.56