Hi, I'm a psych major and don't know much about stats. I'm struggling with this practice question, preparing for a test.
70 boxes of a supposed mean 250 pens each have been sent to the office. The company says the standard deviation is 5. Having had a secretary count all the pens, he found that the mean is 232 pens. Should the boss of the office suspect that pen gnomes of some sort are stealing pens?