Finding the Fourth Proportional to 111.05, 166.46 and 83.91

Step by Step Solution

1. Step 1: Write the proportion equation
   111.05 : 166.46 = 83.91 : x
2. Step 2: Convert to fraction form
   111.05/166.46 = 83.91/x
3. Step 3: Cross multiply
   111.05x = 166.46 × 83.91
4. Step 4: Simplify right side
   111.05x = 13,967.24
5. Step 5: Solve for x
   x = 13,967.24/111.05
6. Step 6: Final answer
   x = 125.78