The Following Data Give the Number of Computer Units Sold

Essay

The following data give the number of computer units sold per day by a random sample of six salespersons before and after a bonus plan was implemented. $\begin{array}{ll}\text { Salesperson } & \text { Before } & \text { After }\\1&3 & 6 \\2&7 & 5 \\3&6 & 6 \\4&8 & 7 \\5&7 & 8 \\6&9 & 8\end{array}$ At 95% confidence, test to see if the bonus plan was effective. That is, did the bonus plan actually increase sales?