1. Statistical studies in which researchers do not control variables of interest are

a. experimental studies

b. uncontrolled experimental studies

c. not of any value

d. observational studies

2. Statistical studies in which researchers control variables of interest are

a. experimental studies

b. control observational studies

c. non experimental studies

d. observational studies

3. A portion of the population selected to represent the population is called

a. statistical inference

b. descriptive statistics

c. a census

d. a sample

4. In a sample of 800 students in a university, 160, or 20%, are Business majors. Based on the above information, the school's paper reported that "20% of all the students at the university are Business majors." This report is an example of

a. a sample

b. a population

c. statistical inference

d. descriptive statistics

5. Six hundred residents of a city are polled to obtain information on voting intentions in an upcoming city election. The six hundred residents in this study is an example of a(n)

a. census

b. sample

c. observation

d. population

6. Since a sample is a subset of the population, a percentage that is calculated from the sample data

a. is always smaller than the corresponding percentage from the population

b. is always larger than the corresponding percentage from the population

c. must be equal to the corresponding percentage from the population

d. can be larger, smaller, or equal to the corresponding percentage from the

7. A tabular method that can be used to summarize the data on two variables simultaneously is called

a. simultaneous equations

b. a crosstabulation

c. a histogram

d. a dot plot