Finding the Fourth Proportional to 123.42, 170.71 and 111.17

Step by Step Solution

1. Step 1: Write the proportion equation
   123.42 : 170.71 = 111.17 : x
2. Step 2: Convert to fraction form
   123.42/170.71 = 111.17/x
3. Step 3: Cross multiply
   123.42x = 170.71 × 111.17
4. Step 4: Simplify right side
   123.42x = 18,977.98
5. Step 5: Solve for x
   x = 18,977.98/123.42
6. Step 6: Final answer
   x = 153.76