The National Park Service, as part of their educational outreach, writes materials forstudents to use while in the parks. In a study of the effectiveness of some of thesematerials, a random sample of students was selected to take a short quiz about oaktrees based on these materials. A random sample of professionals also took the quiz.Investigators compared classifications of the "crown shapes" - the general shapes ofthe leafy parts of the trees -- made by students in grades 6 - 12 with classificationsmade by professionals.The observed and expected counts are summarized in the table below along with thevalue of the chi-square statistic and the associated P-value.
a) State the null and alternative hypotheses for this test.
b) Discuss whether the conditions for a chi-square inference procedure are met forthese data.
c) What should the investigators conclude based on the results of the chi-square test?
d) It is possible that an error (Type I or Type II) could occur. Which error might theinvestigators make, based on your answer in part (c)?
Describe this error in thecontext of the question.

Question

The National Park Service, as part of their educational outreach, writes materials forstudents to use while in the parks. In a study of the effectiveness of some of thesematerials, a random sample of students was selected to take a short quiz about oaktrees based on these materials. A random sample of professionals also took the quiz.Investigators compared classifications of the "crown shapes" - the general shapes ofthe leafy parts of the trees -- made by students in grades 6 - 12 with classificationsmade by professionals.The observed and expected counts are summarized in the table below along with thevalue of the chi-square statistic and the associated P-value.  
a) State the null and alternative hypotheses for this test.
b) Discuss whether the conditions for a chi-square inference procedure are met forthese data.
c) What should the investigators conclude based on the results of the chi-square test?
d) It is possible that an error (Type I or Type II) could occur. Which error might theinvestigators make, based on your answer in part (c)?
 Describe this error in thecontext of the question.

Quizplus · Accepted Answer

The Answer of The National Park Service, as part of their educational outreach, writes materials forstudents to use while in the parks. In a study of the effectiveness of some of thesematerials, a random sample of students was selected to take a short quiz about oaktrees based on these materials. A random sample of professionals also took the quiz.Investigators compared classifications of the "crown shapes" - the general shapes ofthe leafy parts of the trees -- made by students in grades 6 - 12 with classificationsmade by professionals.The observed and expected counts are summarized in the table below along with thevalue of the chi-square statistic and the associated P-value.  
a) State the null and alternative hypotheses for this test.
b) Discuss whether the conditions for a chi-square inference procedure are met forthese data.
c) What should the investigators conclude based on the results of the chi-square test?
d) It is possible that an error (Type I or Type II) could occur. Which error might theinvestigators make, based on your answer in part (c)?
 Describe this error in thecontext of the question.

The National Park Service, as Part of Their Educational Outreach