Finding the Fourth Proportional to 111.40, 167.10 and 72.79

Step by Step Solution

1. Step 1: Write the proportion equation
   111.40 : 167.10 = 72.79 : x
2. Step 2: Convert to fraction form
   111.40/167.10 = 72.79/x
3. Step 3: Cross multiply
   111.40x = 167.10 × 72.79
4. Step 4: Simplify right side
   111.40x = 12,162.59
5. Step 5: Solve for x
   x = 12,162.59/111.40
6. Step 6: Final answer
   x = 109.18