Finding the Fourth Proportional to 71.82, 107.76 and 42.96

Step by Step Solution

1. Step 1: Write the proportion equation
   71.82 : 107.76 = 42.96 : x
2. Step 2: Convert to fraction form
   71.82/107.76 = 42.96/x
3. Step 3: Cross multiply
   71.82x = 107.76 × 42.96
4. Step 4: Simplify right side
   71.82x = 4,629.93
5. Step 5: Solve for x
   x = 4,629.93/71.82
6. Step 6: Final answer
   x = 64.47