Finding the Fourth Proportional to 111.11, 166.59 and 53.31

Step by Step Solution

1. Step 1: Write the proportion equation
   111.11 : 166.59 = 53.31 : x
2. Step 2: Convert to fraction form
   111.11/166.59 = 53.31/x
3. Step 3: Cross multiply
   111.11x = 166.59 × 53.31
4. Step 4: Simplify right side
   111.11x = 8,880.91
5. Step 5: Solve for x
   x = 8,880.91/111.11
6. Step 6: Final answer
   x = 79.93