Finding the Fourth Proportional to 92.72, 128.00 and 86.58

Step by Step Solution

1. Step 1: Write the proportion equation
   92.72 : 128.00 = 86.58 : x
2. Step 2: Convert to fraction form
   92.72/128.00 = 86.58/x
3. Step 3: Cross multiply
   92.72x = 128.00 × 86.58
4. Step 4: Simplify right side
   92.72x = 11,081.81
5. Step 5: Solve for x
   x = 11,081.81/92.72
6. Step 6: Final answer
   x = 119.53