Finding the Fourth Proportional to 112.28, 168.42 and 71.76

Step by Step Solution

1. Step 1: Write the proportion equation
   112.28 : 168.42 = 71.76 : x
2. Step 2: Convert to fraction form
   112.28/168.42 = 71.76/x
3. Step 3: Cross multiply
   112.28x = 168.42 × 71.76
4. Step 4: Simplify right side
   112.28x = 12,085.82
5. Step 5: Solve for x
   x = 12,085.82/112.28
6. Step 6: Final answer
   x = 107.64