Finding the Fourth Proportional to 85.94, 128.83 and 69.88

Step by Step Solution

1. Step 1: Write the proportion equation
   85.94 : 128.83 = 69.88 : x
2. Step 2: Convert to fraction form
   85.94/128.83 = 69.88/x
3. Step 3: Cross multiply
   85.94x = 128.83 × 69.88
4. Step 4: Simplify right side
   85.94x = 9,002.64
5. Step 5: Solve for x
   x = 9,002.64/85.94
6. Step 6: Final answer
   x = 104.75