Finding the Fourth Proportional to 112.78, 168.96 and 64.72

Step by Step Solution

1. Step 1: Write the proportion equation
   112.78 : 168.96 = 64.72 : x
2. Step 2: Convert to fraction form
   112.78/168.96 = 64.72/x
3. Step 3: Cross multiply
   112.78x = 168.96 × 64.72
4. Step 4: Simplify right side
   112.78x = 10,935.09
5. Step 5: Solve for x
   x = 10,935.09/112.78
6. Step 6: Final answer
   x = 96.96