Finding the Fourth Proportional to 71.30, 106.72 and 54.09

Step by Step Solution

1. Step 1: Write the proportion equation
   71.30 : 106.72 = 54.09 : x
2. Step 2: Convert to fraction form
   71.30/106.72 = 54.09/x
3. Step 3: Cross multiply
   71.30x = 106.72 × 54.09
4. Step 4: Simplify right side
   71.30x = 5,771.89
5. Step 5: Solve for x
   x = 5,771.89/71.30
6. Step 6: Final answer
   x = 80.95