Finding the Fourth Proportional to 78.72, 118.01 and 38.10

Step by Step Solution

1. Step 1: Write the proportion equation
   78.72 : 118.01 = 38.10 : x
2. Step 2: Convert to fraction form
   78.72/118.01 = 38.10/x
3. Step 3: Cross multiply
   78.72x = 118.01 × 38.10
4. Step 4: Simplify right side
   78.72x = 4,496.18
5. Step 5: Solve for x
   x = 4,496.18/78.72
6. Step 6: Final answer
   x = 57.12