Finding the Fourth Proportional to 86.77, 119.78 and 59.18

Step by Step Solution

1. Step 1: Write the proportion equation
   86.77 : 119.78 = 59.18 : x
2. Step 2: Convert to fraction form
   86.77/119.78 = 59.18/x
3. Step 3: Cross multiply
   86.77x = 119.78 × 59.18
4. Step 4: Simplify right side
   86.77x = 7,088.58
5. Step 5: Solve for x
   x = 7,088.58/86.77
6. Step 6: Final answer
   x = 81.69