2. Identifying populations, samples, statistics, parameters, andvariables

A psychology professor wants to know whether verbal ability is related to memory quality in current first-year students at his small college. Participants in the study (first-year students at his college) complete an online memory task. The students are first shown a list of 60 words. Next they are shown a list that includes 10 words that were on the original list. Then they are asked to identify the words on the second list that appeared on the original list. He uses the percentage of words that were correctly recognized on the original list as his measure of memory quality. He also asks the students to report several characteristics such as their age, gender, and verbal SAT score.

Each of the 500 first-year students (268 males and 232 females) at his school volunteered to participate. The professor chose 50 students at random to complete the memory task and answer the questions. The average percentage of words that were correctly recognized on the original list was 68%. The professor infers that if all 500 first-year students had completed the study, the results would show that an average of 68% (plus or minus sampling error) of the words were correctly recognized as being on the original list.

Which of the following arevariablesin the study?Check all that apply.

1. The students' verbal SAT scores
2. The 500 students
3. The students' percentage of words that were correctly recognized on the original list
4. The 50 students

What is thepopulationin the study?

1. The 68% of words correctly recognized as being on the original list
2. The 500 first-year students at the college
3. The 50 students who participated in the study

What is thesamplein the study?

1. The 68% of words correctly recognized as being on the original list
2. The 50 students who participated in the study
3. The 500 student volunteers

What is an example of astatisticin the study?

1. 232 females and 268 males
2. 68%, the average percentage of the original list expected to be correctly recognized by the 500 students
3. 68%, the average percentage of words that were correctly recognized as being from the original list by the 50 students

What is an example of aparameterin the study?

1. 50 students
2. The actual average percentage of words that would be correctly recognized as being from the original list by the 500 first-year students
3. 68% of words that were correctly recognized on the original list by the 50 first-year students

What is an example of the professor usingdescriptive statistics?

1. He infers that if all 500 students had done the experiment, the results would show that an average of 68% (plus or minus sampling error) of the words were correctly recognized as being on the original list.
2. He characterizes the first-year students at the college as consisting of 268 males and 232 females.
3. He randomly chooses the 50 students to represent the 500 volunteers.

What is an example of the professor usinginferential statistics?

1. He characterizes the first-year students at the college as consisting of 268 males and 232 females.
2. He infers that if all 500 students had done the experiment, the results would show that an average of 68% (plus or minus sampling error) of the words were correctly recognized as being on the original list.
3. He reports that the average percentage of words that were correctly recognized on the original list was 68%.