Finding the Fourth Proportional to 86.06, 128.52 and 69.83

Step by Step Solution

1. Step 1: Write the proportion equation
   86.06 : 128.52 = 69.83 : x
2. Step 2: Convert to fraction form
   86.06/128.52 = 69.83/x
3. Step 3: Cross multiply
   86.06x = 128.52 × 69.83
4. Step 4: Simplify right side
   86.06x = 8,974.55
5. Step 5: Solve for x
   x = 8,974.55/86.06
6. Step 6: Final answer
   x = 104.28