Finding the Fourth Proportional to 111.05, 166.69 and 82.07

Step by Step Solution

1. Step 1: Write the proportion equation
   111.05 : 166.69 = 82.07 : x
2. Step 2: Convert to fraction form
   111.05/166.69 = 82.07/x
3. Step 3: Cross multiply
   111.05x = 166.69 × 82.07
4. Step 4: Simplify right side
   111.05x = 13,679.21
5. Step 5: Solve for x
   x = 13,679.21/111.05
6. Step 6: Final answer
   x = 123.19