Finding the Fourth Proportional to 111.25, 166.71 and 72.64

Step by Step Solution

1. Step 1: Write the proportion equation
   111.25 : 166.71 = 72.64 : x
2. Step 2: Convert to fraction form
   111.25/166.71 = 72.64/x
3. Step 3: Cross multiply
   111.25x = 166.71 × 72.64
4. Step 4: Simplify right side
   111.25x = 12,108.98
5. Step 5: Solve for x
   x = 12,108.98/111.25
6. Step 6: Final answer
   x = 108.85