1. **Problem statement:** We need to find the second number in a sequence of 3 consecutive even numbers whose sum is 78. 2. **Define variables:** Let the first even number be $x$. Since the numbers are consecutive even numbers, the second number is $x+2$ and the third number is $x+4$. 3. **Write the equation for the sum:** $$x + (x+2) + (x+4) = 78$$ 4. **Simplify the equation:** $$3x + 6 = 78$$ 5. **Solve for $x$:** $$3x = 78 - 6$$ $$3x = 72$$ $$x = \frac{72}{3} = 24$$ 6. **Find the second number:** $$x + 2 = 24 + 2 = 26$$ **Answer:** The second number in the sequence is $26$.