Finding the Fourth Proportional to 111.31, 166.73 and 72.65

Step by Step Solution

1. Step 1: Write the proportion equation
   111.31 : 166.73 = 72.65 : x
2. Step 2: Convert to fraction form
   111.31/166.73 = 72.65/x
3. Step 3: Cross multiply
   111.31x = 166.73 × 72.65
4. Step 4: Simplify right side
   111.31x = 12,112.99
5. Step 5: Solve for x
   x = 12,112.99/111.31
6. Step 6: Final answer
   x = 108.82