Finding the Fourth Proportional to 108.72, 162.72 and 76.56

Step by Step Solution

1. Step 1: Write the proportion equation
   108.72 : 162.72 = 76.56 : x
2. Step 2: Convert to fraction form
   108.72/162.72 = 76.56/x
3. Step 3: Cross multiply
   108.72x = 162.72 × 76.56
4. Step 4: Simplify right side
   108.72x = 12,457.84
5. Step 5: Solve for x
   x = 12,457.84/108.72
6. Step 6: Final answer
   x = 114.59