Welcome to the Quiz!
This quiz contains 13 questions from a mix of 1 subtopics.
Which of the following is true about the interpretation of correlation coefficients?
a coefficient near -1 indicates a strong negative correlation
a coefficient near -1 indicates no correlation
a coefficient near 0 indicates a perfect linear correlation
a coefficient near +1 indicates a strong negative correlation
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Which of the following is true about a positive correlation?
one variable increases while the other decreases
the correlation coefficient is always close to 0
there is no clear relationship between the variables
both variables increase or decrease together
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What is the purpose of comparing the calculated correlation coefficient to a critical value at a 5% significance level?
to determine the strength of the correlation
to determine the significance of the correlation
to determine the direction of the correlation
to determine the linearity of the correlation
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What does a correlation coefficient of 1 indicate?
no correlation
a perfect positive linear correlation
a perfect negative linear correlation
a strong negative correlation
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Which of the following is true about a negative correlation?
there is no clear relationship between the variables
one variable increases while the other decreases
both variables increase together
both variables decrease together
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What does a correlation coefficient close to 0 suggest?
a strong positive correlation
a strong negative correlation
no correlation
a perfect linear correlation
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Which statistical test is used to assess the relationship between two continuous variables that are not normally distributed?
Pearson's linear correlation
student's t-test
chi-squared test
Spearman's rank correlation
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When calculating the ranks for Spearman's rank correlation, what should you do if two values are the same for one variable?
(Select all that apply)
give them the same rank
assign them consecutive ranks
give them an average rank
exclude the data points
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What does an r value near +1 indicate in Pearson's correlation?
no correlation
a strong positive correlation
a strong negative correlation
a perfect negative linear correlation
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In the Pearson's correlation coefficient formula, what does xˉ represent?
the difference between each x value and the mean of x
the mean of all x values
the sum of all x values
the standard deviation of x
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In Spearman's rank correlation, what is the purpose of converting the raw data values into ranks?
to eliminate the effect of outliers
to make the data easier to interpret
to compare variables measured on different scales
to normalise the data distribution
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What is the main difference between Spearman's rank correlation and Pearson's linear correlation?
Spearman's is used for continuous variables, while Pearson's is used for discontinuous variables
Spearman's is used for a small sample size, while Pearson's is used for a large sample size
Spearman's is used for non-normally distributed data, while Pearson's is used for normally distributed data
Spearman's measures the strength of a non-linear relationship, while Pearson's measures the strength of a linear relationship
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Which of the following is true about Pearson's correlation coefficient (r)?
it is used when one or both variables are not normally distributed
it measures the strength of a non-linear relationship
it is used for continuous variables
it is used for discontinuous variables
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