数据分析习题1(1)

Question 1

Which of the following classifications of variable types is false?

Your Answer Score Explanation

Student height → continuous numerical

Population of each state in the US → continuous numerical Correct 1.00 Counted data are

can’t take on no

Customer satisfaction: very unsatisfied, unsatisfied, satisfied, very satisfied → ordinal categorical

Whether a student has previously taken a statistics course → categorical

Total 1.00 / 1.00

Question ExplanationThis question refers to the following learning objective(s):

Identify variables as numerical and categorical.

? If variable is numerical, further classify as continuous or discrete based on whether or not the variable can take on an infinite number of values or only non-negative whole numbers, respectively.

? If variable is categorical, determine if it is ordinal based on whether or not the levels have a natural ordering.

Question 2

A study is designed to test the effect of type of light on exam performance of students. 180 students are randomly assigned to three classrooms: one that is dimly lit, another with yellow lighting, and a third with white fluorescent lighting, and given the same exam. Which of the following correctlyidentifies the variables used in the study as explanatory and response?

Your Answer Score Explanation

explanatory:exam performance

response: type of light (categorical with 3 levels)

explanatory:dimly yellow, white fluorescent response: performance

lit,

exam

explanatory:exam performance

response: dimly lit, yellow, white fluorescent

explanatory:type of light Correct 1.00 (categorical with 3 levels) response: performance

exam

We are interested in the effect of type of light on e

light is the explanatory variable and exam perform

light is a categorical variable that can take on three

white light). These possible values are called levels

Total 1.00 / 1.00

Question ExplanationThis question refers to the following learning objective(s):

Identify the explanatory variable in a pair of variables as the variable suspected of affecting the other, however note that labeling variables as explanatory and response does not guarantee that the relationship between the two is actually causal, even if there is an association identified between the two variables.

Question 3

True or False: If subjects are randomly assigned to treatments, conclusions can be generalized to the population.

Your Answer

Score Explanation

False

True Inorrect 0.00 Random assignment allows us to make causal conclusions. Fosampling.

Total 0.00 / 1.00

Question ExplanationThis question refers to the following learning objective(s):

Classify a study as observational or experimental, and determine whether the study’s results can be generalized to the population and whether they suggest correlation or causation.

? If random sampling has been employed in data collection, the results should be generalizable to the target population.

? If random assignment has been employed in study design, the results suggest causality.

Question 4

An extraneous variable that is related to the explanatory and response variables and that prevents us from deducing causal relationships based on observational studies is called a .

Answer for Question 4You entered: