91Ó°ÊÓ

A factory quality control manager decides to investigate the percentage of defective items produced each day. Within a given work week (Monday through Friday) the percentage of defective items produced was \(2 \%, 1.4 \%, 4 \%, 3 \%, 2.2 \%\). (a) Calculate the mean for these data. (b) Calculate the standard deviation for these data, showing each step in detail.

Students in an AP Statistics class were asked how many hours of television they watch per week (including online streaming). This sample yielded an average of 4.71 hours, with a standard deviation of 4.18 hours. Is the distribution of number of hours students watch television weekly symmetric? If not, what shape would you expect this distribution to have? Explain your reasoning.

The average on a history exam (scored out of 100 points) was \(85,\) with a standard deviation of 15 . Is the distribution of the scores on this exam symmetric? If not, what shape would you expect this distribution to have? Explain your reasoning.