Finding the Fourth Proportional to 86.02, 128.78 and 82.95

Step by Step Solution

1. Step 1: Write the proportion equation
   86.02 : 128.78 = 82.95 : x
2. Step 2: Convert to fraction form
   86.02/128.78 = 82.95/x
3. Step 3: Cross multiply
   86.02x = 128.78 × 82.95
4. Step 4: Simplify right side
   86.02x = 10,681.69
5. Step 5: Solve for x
   x = 10,681.69/86.02
6. Step 6: Final answer
   x = 124.17