#1
In a scatter plot, what does it suggest if the points form a tight cluster around a line that slopes upward from left to right?
There is a positive correlation
ExplanationTight cluster with upward slope suggests positive correlation.
#2
What does a correlation coefficient of 0 indicate?
No correlation
ExplanationCorrelation coefficient 0 indicates no correlation.
#3
What does a correlation coefficient of 1 indicate?
A perfect positive correlation
ExplanationCorrelation coefficient 1 indicates perfect positive correlation.
#4
What does a correlation coefficient of -1 indicate?
A perfect negative correlation
ExplanationCorrelation coefficient -1 indicates perfect negative correlation.
#5
Which of the following correlation coefficients represents no linear relationship between two variables?
0
ExplanationCorrelation coefficient 0 represents no linear relationship.
#6
What does a correlation coefficient measure?
Strength and direction of the linear relationship between two variables
ExplanationCorrelation coefficient measures linear relationship strength and direction.
#7
Which of the following correlation coefficients represents a perfect negative linear relationship?
-1
ExplanationCorrelation coefficient -1 represents perfect negative linear relationship.
#8
What is the range of values for a correlation coefficient?
[-1, 1]
ExplanationCorrelation coefficient ranges from -1 to 1.
#9
Which of the following scatter plots suggests a stronger correlation?
A scatter plot with points forming a tight cluster around a straight line
ExplanationA tight cluster around a straight line suggests stronger correlation.
#10
If the correlation coefficient between two variables is -0.8, what does this indicate?
A strong negative correlation
ExplanationCorrelation coefficient -0.8 indicates a strong negative correlation.
#11
Which of the following statements about correlation is FALSE?
Correlation implies causation
ExplanationCorrelation does not imply causation.
#12
What is the formula to calculate the correlation coefficient between two variables X and Y?
(sum(X - mean(X)) * (Y - mean(Y))) / sqrt(sum((X - mean(X))^2) * sum((Y - mean(Y))^2))
ExplanationCorrelation coefficient formula: (Σ((X - mean(X))(Y - mean(Y))) / sqrt(Σ((X - mean(X))^2) * Σ((Y - mean(Y))^2))).
#13
When is it appropriate to use Pearson correlation coefficient?
When the relationship between variables is linear
ExplanationPearson correlation is appropriate when the relationship is linear.
#14
Which of the following statements about correlation is TRUE?
A correlation of -1 indicates a perfect positive correlation
ExplanationCorrelation -1 indicates perfect positive correlation.
#15
What is the primary limitation of correlation analysis?
It cannot determine causation
ExplanationCorrelation analysis cannot determine causation.