Define the purpose of inferential statistics.
Q. 2Define the purpose of descriptive statistics.
Q. 3A researcher is conducting a survey among students to determine their mean age. Data is collected by asking the age of a simple random sample of 150 students. The researcher simply asked the ages of these students. The results of this study, if applied to all students in the university, are questionable because of
a. lack of accuracy.
b. selection bias.
c. nonresponse bias.
d. response bias.
Q. 4People claim that only 5 of the students who take the introductory statistics course will continue their education in statistics. The Statistics Department believes that this value is too low and decides to take a sample of 20 students out of the 315 students registered that semester. Of the 20 students, 7 (or 35) say they will continue to study more statistics. It turns out that the 20 students selected for this study were those that received the highest scores on the first quiz. The results of this study, if applied to all students who take the introductory statistics course, are questionable because of
a. lack of accuracy.
b. selection bias.
c. nonresponse bias.
d. response bias.
Q. 5In the College of Engineering exams aren't proctored. Students are required to write out the University honor code. They sign their name to pledge that they didn't cheat. But the engineering professors cannot observe if students cheat or not. One way to collect data on this topic would be to use an exit poll: Have a Graduate Student Instructor ask the students if they cheated on the exam after the student has left the exam room. The results of this study, if applied to all students in the College of Engineering, are questionable because of
a. lack of accuracy.
b. selection bias.
c. nonresponse bias.
d. response bias.
Q. 6A weight-loss company is trying to promote its product. Based on a sample of 10 of their clients they model the relationship between starting weight and weight after 4 weeks using their product. It turns out that these 10 clients were selected because they had lost a decent amount of weight in 4 weeks. Clients who had lost hardly any weight or even gained weight were not included for this study. The results of this study, if applied to all clients, are questionable because of
a. lack of accuracy.
b. selection bias.
c. nonresponse bias.
d. response bias.
Q. 7When a representative sample is selected but respondents give answers that are different from their true opinions, the problem is called
a. lack of accuracy.
b. selection bias.
c. nonresponse bias.
d. response bias.
Q. 8When a representative sample is selected but only a small proportion are actually contacted, the problem is called
a. lack of accuracy.
b. selection bias.
c. nonresponse bias.
d. response bias.