Finding the Fourth Proportional to 111.79, 167.45 and 72.15

Step by Step Solution

1. Step 1: Write the proportion equation
   111.79 : 167.45 = 72.15 : x
2. Step 2: Convert to fraction form
   111.79/167.45 = 72.15/x
3. Step 3: Cross multiply
   111.79x = 167.45 × 72.15
4. Step 4: Simplify right side
   111.79x = 12,081.52
5. Step 5: Solve for x
   x = 12,081.52/111.79
6. Step 6: Final answer
   x = 108.07