Finding the Fourth Proportional to 111.78, 166.59 and 107.87

Step by Step Solution

1. Step 1: Write the proportion equation
   111.78 : 166.59 = 107.87 : x
2. Step 2: Convert to fraction form
   111.78/166.59 = 107.87/x
3. Step 3: Cross multiply
   111.78x = 166.59 × 107.87
4. Step 4: Simplify right side
   111.78x = 17,969.23
5. Step 5: Solve for x
   x = 17,969.23/111.78
6. Step 6: Final answer
   x = 160.76