Finding the Fourth Proportional to 111.72, 166.40 and 105.94

Step by Step Solution

1. Step 1: Write the proportion equation
   111.72 : 166.40 = 105.94 : x
2. Step 2: Convert to fraction form
   111.72/166.40 = 105.94/x
3. Step 3: Cross multiply
   111.72x = 166.40 × 105.94
4. Step 4: Simplify right side
   111.72x = 17,628.42
5. Step 5: Solve for x
   x = 17,628.42/111.72
6. Step 6: Final answer
   x = 157.79