Finding the Fourth Proportional to 42.42, 58.47 and 39.72

Step by Step Solution

1. Step 1: Write the proportion equation
   42.42 : 58.47 = 39.72 : x
2. Step 2: Convert to fraction form
   42.42/58.47 = 39.72/x
3. Step 3: Cross multiply
   42.42x = 58.47 × 39.72
4. Step 4: Simplify right side
   42.42x = 2,322.43
5. Step 5: Solve for x
   x = 2,322.43/42.42
6. Step 6: Final answer
   x = 54.75