Finding the Fourth Proportional to 78.82, 118.14 and 42.72

Step by Step Solution

1. Step 1: Write the proportion equation
   78.82 : 118.14 = 42.72 : x
2. Step 2: Convert to fraction form
   78.82/118.14 = 42.72/x
3. Step 3: Cross multiply
   78.82x = 118.14 × 42.72
4. Step 4: Simplify right side
   78.82x = 5,046.94
5. Step 5: Solve for x
   x = 5,046.94/78.82
6. Step 6: Final answer
   x = 64.03