Straighterline Introduction to Statistics|
Questions Answered 100%
Correct/Verified Solutions
Finding an outlier using IQR - ANSWER An observation is considered a suspected outlier if it is:
less than Q1 - 1.5(IQR), or
more than Q3 + 1.5(IQR).
Interpreting scatterplots:
1. positive relationship displays as
2. negative relationship displays as - ANSWER 1. upward slope
2. downward slope
Interpreting Scatterplots:
How to tell if a linear relationship is strong or weak - ANSWER closer to -1 is a strong negative
linear relationship
closer to +1 is a strong positive linear relationship
close to 0 is a weak linear relationship
Interpreting Scatterplots:
Linear regression - ANSWER Finding the line that best fits the pattern of the linear relationship (the
line that describes how the response variable linearly depends on the explanatory variable
Interpreting Scatterplots:
Least Squares Regression Line - ANSWER Has the smallest sum of squared vertical deviations of
the data points from the line.
, Interpreting Scatterplots:
Extrapolation - ANSWER Prediction for ranges of the explanatory variable that are not in
the data; is not reliable and should be avoided
Association (does/does not) imply causation. - ANSWER Does not
Lurking Variable - ANSWER a variable that is not among the explanatory or response variables in
a study, but could substantially affect your interpretation of the relationship among those
variables
Simpson's paradox - ANSWER When a lurking variable causes you to rethink the direction of
an association
Probability sampling plan - ANSWER any sampling plan that relies on random selection (avoids
bias).
Simple Random Sampling - ANSWER Every member of the population has an equal
probability of being selected for the sample
Cluster Sampling - ANSWER Used when the population is naturally divided into groups. Take
a random sample of clusters and use all individuals within those clusters as the sample.
Stratified sampling - ANSWER Used when the population is naturally divided into sub-
populations called stratum. Choose a simple random sample from each stratum and use
these together as the sample.
Multistage sampling - ANSWER a probability sampling technique involving at least two stages: a
random sample of clusters followed by a random sample of people within the selected clusters
Questions Answered 100%
Correct/Verified Solutions
Finding an outlier using IQR - ANSWER An observation is considered a suspected outlier if it is:
less than Q1 - 1.5(IQR), or
more than Q3 + 1.5(IQR).
Interpreting scatterplots:
1. positive relationship displays as
2. negative relationship displays as - ANSWER 1. upward slope
2. downward slope
Interpreting Scatterplots:
How to tell if a linear relationship is strong or weak - ANSWER closer to -1 is a strong negative
linear relationship
closer to +1 is a strong positive linear relationship
close to 0 is a weak linear relationship
Interpreting Scatterplots:
Linear regression - ANSWER Finding the line that best fits the pattern of the linear relationship (the
line that describes how the response variable linearly depends on the explanatory variable
Interpreting Scatterplots:
Least Squares Regression Line - ANSWER Has the smallest sum of squared vertical deviations of
the data points from the line.
, Interpreting Scatterplots:
Extrapolation - ANSWER Prediction for ranges of the explanatory variable that are not in
the data; is not reliable and should be avoided
Association (does/does not) imply causation. - ANSWER Does not
Lurking Variable - ANSWER a variable that is not among the explanatory or response variables in
a study, but could substantially affect your interpretation of the relationship among those
variables
Simpson's paradox - ANSWER When a lurking variable causes you to rethink the direction of
an association
Probability sampling plan - ANSWER any sampling plan that relies on random selection (avoids
bias).
Simple Random Sampling - ANSWER Every member of the population has an equal
probability of being selected for the sample
Cluster Sampling - ANSWER Used when the population is naturally divided into groups. Take
a random sample of clusters and use all individuals within those clusters as the sample.
Stratified sampling - ANSWER Used when the population is naturally divided into sub-
populations called stratum. Choose a simple random sample from each stratum and use
these together as the sample.
Multistage sampling - ANSWER a probability sampling technique involving at least two stages: a
random sample of clusters followed by a random sample of people within the selected clusters
