Finding the Fourth Proportional to 112.72, 168.72 and 72.16

Step by Step Solution

1. Step 1: Write the proportion equation
   112.72 : 168.72 = 72.16 : x
2. Step 2: Convert to fraction form
   112.72/168.72 = 72.16/x
3. Step 3: Cross multiply
   112.72x = 168.72 × 72.16
4. Step 4: Simplify right side
   112.72x = 12,174.84
5. Step 5: Solve for x
   x = 12,174.84/112.72
6. Step 6: Final answer
   x = 108.01