Finding the Fourth Proportional to 111.06, 166.42 and 99.59

Step by Step Solution

1. Step 1: Write the proportion equation
   111.06 : 166.42 = 99.59 : x
2. Step 2: Convert to fraction form
   111.06/166.42 = 99.59/x
3. Step 3: Cross multiply
   111.06x = 166.42 × 99.59
4. Step 4: Simplify right side
   111.06x = 16,573.06
5. Step 5: Solve for x
   x = 16,573.06/111.06
6. Step 6: Final answer
   x = 149.23