Finding the Fourth Proportional to 86.58, 119.33 and 64.71

Step by Step Solution

1. Step 1: Write the proportion equation
   86.58 : 119.33 = 64.71 : x
2. Step 2: Convert to fraction form
   86.58/119.33 = 64.71/x
3. Step 3: Cross multiply
   86.58x = 119.33 × 64.71
4. Step 4: Simplify right side
   86.58x = 7,721.52
5. Step 5: Solve for x
   x = 7,721.52/86.58
6. Step 6: Final answer
   x = 89.18