Finding the Fourth Proportional to 67.20, 100.80 and 34.72

Step by Step Solution

1. Step 1: Write the proportion equation
   67.20 : 100.80 = 34.72 : x
2. Step 2: Convert to fraction form
   67.20/100.80 = 34.72/x
3. Step 3: Cross multiply
   67.20x = 100.80 × 34.72
4. Step 4: Simplify right side
   67.20x = 3,499.78
5. Step 5: Solve for x
   x = 3,499.78/67.20
6. Step 6: Final answer
   x = 52.08