Finding the Fourth Proportional to 71.76, 107.59 and 53.72

Step by Step Solution

1. Step 1: Write the proportion equation
   71.76 : 107.59 = 53.72 : x
2. Step 2: Convert to fraction form
   71.76/107.59 = 53.72/x
3. Step 3: Cross multiply
   71.76x = 107.59 × 53.72
4. Step 4: Simplify right side
   71.76x = 5,779.73
5. Step 5: Solve for x
   x = 5,779.73/71.76
6. Step 6: Final answer
   x = 80.54