Finding the Fourth Proportional to 85.82, 128.79 and 73.89

Step by Step Solution

1. Step 1: Write the proportion equation
   85.82 : 128.79 = 73.89 : x
2. Step 2: Convert to fraction form
   85.82/128.79 = 73.89/x
3. Step 3: Cross multiply
   85.82x = 128.79 × 73.89
4. Step 4: Simplify right side
   85.82x = 9,516.29
5. Step 5: Solve for x
   x = 9,516.29/85.82
6. Step 6: Final answer
   x = 110.89