Finding the Fourth Proportional to 111.96, 168.05 and 57.89

Step by Step Solution

1. Step 1: Write the proportion equation
   111.96 : 168.05 = 57.89 : x
2. Step 2: Convert to fraction form
   111.96/168.05 = 57.89/x
3. Step 3: Cross multiply
   111.96x = 168.05 × 57.89
4. Step 4: Simplify right side
   111.96x = 9,728.55
5. Step 5: Solve for x
   x = 9,728.55/111.96
6. Step 6: Final answer
   x = 86.89