Finding the Fourth Proportional to 123.39, 170.42 and 111.73

Step by Step Solution

1. Step 1: Write the proportion equation
   123.39 : 170.42 = 111.73 : x
2. Step 2: Convert to fraction form
   123.39/170.42 = 111.73/x
3. Step 3: Cross multiply
   123.39x = 170.42 × 111.73
4. Step 4: Simplify right side
   123.39x = 19,041.03
5. Step 5: Solve for x
   x = 19,041.03/123.39
6. Step 6: Final answer
   x = 154.32