#1
Which of the following correlation coefficients represents a perfect positive linear relationship?
1
ExplanationPerfect positive linear correlation.
#2
In a scatter plot, if the points tend to form a straight line sloping upwards from left to right, what type of correlation is likely present?
Positive correlation
ExplanationPositive correlation indicated.
#3
Which of the following statements about correlation coefficients is correct?
Correlation coefficients range from -1 to 1
ExplanationRange of correlation coefficients.
#4
What is the purpose of a scatter plot in statistical analysis?
To visualize the relationship between two variables
ExplanationVisualize relationship between variables.
#5
Which of the following is a measure of central tendency?
Median
ExplanationMeasure of central tendency.
#6
What is Pearson's correlation coefficient used for?
To measure the strength and direction of a linear relationship between two variables
ExplanationMeasures linear relationship strength and direction.
#7
Which statistical test is used to determine if there is a significant association between two categorical variables?
Chi-squared test
ExplanationTests association between categorical variables.
#8
What does the coefficient of determination (R-squared) measure?
The proportion of the variance in the dependent variable that is predictable from the independent variable
ExplanationMeasures predictability of dependent variable variance.
#9
Which of the following statements about correlation is true?
Correlation does not imply causation
ExplanationCorrelation ≠ causation.
#10
What is the purpose of regression analysis?
To predict the value of a dependent variable based on one or more independent variables
ExplanationPredict dependent variable from independent.
#11
What does the slope of the regression line represent in linear regression?
The change in the dependent variable for a one-unit change in the independent variable
ExplanationChange in dependent variable per unit change in independent.
#12
Which of the following statements about outliers is true?
Outliers can significantly affect statistical analyses
ExplanationOutliers impact statistical analyses.
#13
What does the p-value represent in hypothesis testing?
The probability of observing the data given that the null hypothesis is true
ExplanationProbability of data given null hypothesis.
#14
What is multicollinearity in regression analysis?
When predictor variables are correlated with each other
ExplanationCorrelation among predictor variables.
#15
What is the formula for calculating the slope (β) in simple linear regression?
(Σxy) / (Σx^2)
ExplanationSimple linear regression slope formula.
#16
What does the term 'heteroscedasticity' refer to in regression analysis?
The unequal variance of residuals across levels of the independent variable
ExplanationUnequal variance of residuals across levels of independent variable.
#17
Which of the following is NOT an assumption of linear regression?
Normality of independent variables
ExplanationNot assuming normality of independent variables.
#18
In regression analysis, what does the term 'collinearity' refer to?
The perfect linear relationship between predictor variables
ExplanationPerfect linear relationship between predictors.