Finding the Fourth Proportional to 71.09, 106.69 and 40.72

Step by Step Solution

1. Step 1: Write the proportion equation
   71.09 : 106.69 = 40.72 : x
2. Step 2: Convert to fraction form
   71.09/106.69 = 40.72/x
3. Step 3: Cross multiply
   71.09x = 106.69 × 40.72
4. Step 4: Simplify right side
   71.09x = 4,344.05
5. Step 5: Solve for x
   x = 4,344.05/71.09
6. Step 6: Final answer
   x = 61.10