Finding the Fourth Proportional to 139.12, 191.88 and 111.38

Step by Step Solution

1. Step 1: Write the proportion equation
   139.12 : 191.88 = 111.38 : x
2. Step 2: Convert to fraction form
   139.12/191.88 = 111.38/x
3. Step 3: Cross multiply
   139.12x = 191.88 × 111.38
4. Step 4: Simplify right side
   139.12x = 21,371.59
5. Step 5: Solve for x
   x = 21,371.59/139.12
6. Step 6: Final answer
   x = 153.62