\({1 \over 2^3} \times {1 \over 2} \times {4 \choose 1} = {4 \over 16} = \color{brown}\boxed {1\over 4}\)
Explanation:
There is a \({1 \over 2} \times {1 \over 2} \times {1 \over 2} \) chance of the successes (\(3\) tails)
There is a \(1 \over 2\) chance of failure (\(1\) head)
There are \(4 \choose 1\) ways to order the failure (the same as \(4 \choose 3\), which counts the ways to order the successes.)