Finding the Fourth Proportional to 42.56, 58.71 and 40.72

Step by Step Solution

1. Step 1: Write the proportion equation
   42.56 : 58.71 = 40.72 : x
2. Step 2: Convert to fraction form
   42.56/58.71 = 40.72/x
3. Step 3: Cross multiply
   42.56x = 58.71 × 40.72
4. Step 4: Simplify right side
   42.56x = 2,390.67
5. Step 5: Solve for x
   x = 2,390.67/42.56
6. Step 6: Final answer
   x = 56.17