Finding the Fourth Proportional to 71.72, 107.48 and 55.42

Step by Step Solution

1. Step 1: Write the proportion equation
   71.72 : 107.48 = 55.42 : x
2. Step 2: Convert to fraction form
   71.72/107.48 = 55.42/x
3. Step 3: Cross multiply
   71.72x = 107.48 × 55.42
4. Step 4: Simplify right side
   71.72x = 5,955.73
5. Step 5: Solve for x
   x = 5,955.73/71.72
6. Step 6: Final answer
   x = 83.04