Finding the Fourth Proportional to 71.72, 106.85 and 67.30

Step by Step Solution

1. Step 1: Write the proportion equation
   71.72 : 106.85 = 67.30 : x
2. Step 2: Convert to fraction form
   71.72/106.85 = 67.30/x
3. Step 3: Cross multiply
   71.72x = 106.85 × 67.30
4. Step 4: Simplify right side
   71.72x = 7,191.01
5. Step 5: Solve for x
   x = 7,191.01/71.72
6. Step 6: Final answer
   x = 100.26