Finding the Fourth Proportional to 42.05, 62.64 and 39.72

Step by Step Solution

1. Step 1: Write the proportion equation
   42.05 : 62.64 = 39.72 : x
2. Step 2: Convert to fraction form
   42.05/62.64 = 39.72/x
3. Step 3: Cross multiply
   42.05x = 62.64 × 39.72
4. Step 4: Simplify right side
   42.05x = 2,488.06
5. Step 5: Solve for x
   x = 2,488.06/42.05
6. Step 6: Final answer
   x = 59.17