A Pitching Machine Throws Baseballs That Are Either Strikes (S)or

A pitching machine throws baseballs that are either strikes (S)or balls (B). A coach records whether each ball
thrown during batting practice is a strike or a ball. Find the standardized test statistic z to test for randomness. $$\begin{array} { l l l l l l l l l l } \text { B } & \text { B } & \text { S } & \text { B } & \text { S } & \text { S } & \text { B } & \text { B } & \text { S } & \text { B } \\\text { B } & \text { B } & \text { B } & \text { S } & \text { B } & \text { S } & \text { S } & \text { S } & \text { S } & \text { S } \\\text { B } & \text { B } & \text { B } & \text { B } & \text { S } & \text { B } & \text { B } & \text { S } & \text { B } & \text { B } \\\text { B } & \text { S } & \text { S } & \text { S } & \text { B } & \text { S } & \text { S } & \text { S } & \text { B } & \text { B } \\\text { B } & \text { B } & \text { B } & \text { S } & \text { S } & \text { S } & \text { S } & \text { S } & \text { S } & \text { S }\end{array}$$