Is a glass manufacturer that produces glasses of every shape and type recently it is signed a contract to supply round glasses to switch, a swiss watch manufacturer. the specifications require the diameter to be between 4.96 cm and 5.04cm. with the current production process, vetro inc. manages to produce glasses whose diameter is, on average, equal to 5cm ; however, a closer inspection reveals some variability in the process, with the diameter of the glass being normally distributed with statndard deviation equal to 0.0lcm 1, what is the capability index of vero inc ?
2, what is the maxmum standard deviation allowed for the process to meet the rigorous six-sigma standards?

The authors of the paper "fudging the numbers: distributing chocolate influences student evaluations of an undergraduate course"† carried out a study to see if events unrelated to an undergraduate course could affect student evaluations. students enrolled in statistics courses taught by the same instructor participated in the study. all students attended the same lectures and one of six discussion sections that met once a week. at the end of the course, the researchers chose three of the discussion sections to be the "chocolate group." students in these three sections were offered chocolate prior to having them fill out course evaluations. students in the other three sections were not offered chocolate. the researchers concluded that "overall, students offered chocolate gave more positive evaluations than students not offered chocolate." indicate whether the study is an observational study or an experiment. give a brief explanation for your choice.