Eight Instances of a Worker Doing a Task Were Observed

Short Answer

Eight instances of a worker doing a task were observed as follows: $$\begin{array} { l r r r r r r r r } \text { Observation } & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 \\\hline \text { Time (seconds) } & 17 & 18 & 15 & 14 & 13 & 15 & 16 & 12\end{array}$$ How many observations would be needed to be 95.44 percent confident that the maximum error in the observed time is one second? Assume that the standard deviation of the task time is two seconds.