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Flashcards: Scatterplots 40 Flashcards 
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Card: 1 / 40 
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What is a scatterplot? |
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A scatterplot is a type of data visualization that shows the relationship between two quantitative variables. Each point on the scatterplot represents an observation in the dataset, with the x-axis representing one variable and the y-axis representing the other. |
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Card: 3 / 40
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How can you determine if there is a correlation between two variables from a scatterplot? |
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You can determine the correlation by observing the pattern of the points. If the points tend to rise together, there is a positive correlation. If one variable increases while the other decreases, there is a negative correlation. If the points are scattered without any clear pattern, there may be no correlation. |
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What does it mean if a scatterplot shows a strong positive correlation? |
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A strong positive correlation in a scatterplot indicates that as one variable increases, the other variable tends to also increase. The points will be closely clustered around a straight line that slopes upward from left to right. |
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Given the scatterplot of height (in inches) vs. weight (in pounds), how would you describe a linear relationship? |
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Card: 8 / 40
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A linear relationship in this context would be indicated by points that closely follow a straight line. For example, if taller individuals tend to weigh more, the points would trend upward in a straight line, suggesting that height and weight are related in a predictable way. |
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Card: 9 / 40
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How can outliers affect the interpretation of a scatterplot? |
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Card: 10 / 40
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Outliers can significantly affect the interpretation of a scatterplot by skewing the perceived relationship between the variables. They may indicate exceptions to the general trend or errors in data collection. It's important to analyze outliers to understand their impact on correlation and regression analysis. |
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Card: 11 / 40
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What is the purpose of the line of best fit in a scatterplot? |
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The line of best fit is a straight line that best represents the data on a scatterplot. It helps to predict values, understand trends, and illustrate the overall direction of the relationship between the two variables. |
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What information can you obtain from the slope of the line of best fit? |
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The slope of the line of best fit indicates the rate of change between the two variables. A positive slope suggests that as one variable increases, the other does as well, while a negative slope indicates an inverse relationship. |
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How do you interpret a scatterplot with no correlation? |
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A scatterplot with no correlation will show points that are widely dispersed without any discernible pattern. This indicates that changes in one variable do not predict changes in the other variable. |
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What is the formula for Pearson's correlation coefficient? |
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Card: 18 / 40
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Pearson's correlation coefficient (r) is calculated as r = (nΣxy - ΣxΣy) / √[(nΣx² - (Σx)²)(nΣy² - (Σy)²)], where n is the number of pairs, Σxy is the sum of the product of paired scores, Σx and Σy are the sums of x scores and y scores respectively. |
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Card: 19 / 40
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If the correlation coefficient is 0.85, how would you describe the relationship between the variables? |
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Card: 20 / 40
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A correlation coefficient of 0.85 indicates a strong positive correlation between the two variables, suggesting that as one variable increases, the other tends to increase as well. |
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What does a correlation coefficient of -1 imply? |
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A correlation coefficient of -1 implies a perfect negative correlation, meaning that as one variable increases, the other variable decreases in a perfectly linear manner. |
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Card: 23 / 40
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In a scatterplot, what does it indicate if the points are clustered tightly around a line? |
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Card: 24 / 40
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If the points are clustered tightly around a line, it indicates a strong correlation between the two variables, suggesting that one variable can reliably predict the other. |
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Card: 25 / 40
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What is the significance of the y-intercept in the context of a scatterplot? |
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Card: 26 / 40
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The y-intercept is the value of y when x is 0. In the context of a scatterplot, it represents the starting point of the line of best fit and can provide insight into the relationship between the variables. |
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How can you identify outliers in a scatterplot? |
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Card: 28 / 40
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Outliers can be identified in a scatterplot as points that lie far away from the overall pattern of the other points. They appear as isolated points that do not fit the trend of the majority. |
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Card: 29 / 40
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What is a residual in the context of scatterplots and regression? |
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Card: 30 / 40
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A residual is the difference between the observed value and the predicted value from the line of best fit. Analyzing residuals helps assess the accuracy of the model. |
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Card: 31 / 40
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How can scatterplots be used to determine causation? |
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While scatterplots can show correlation, they do not determine causation. Additional analysis, experiments, or evidence are required to establish a causal relationship between the variables. |
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What does it mean if a scatterplot has a curved pattern? |
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Card: 34 / 40
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A curved pattern in a scatterplot suggests a non-linear relationship between the variables, indicating that the rate of change varies at different levels of the variables. |
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Fill in the blank: In a scatterplot, a positive slope indicates that as variable x __________ variable y. |
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Card: 36 / 40
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Increases, variable y also increases. |
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Card: 37 / 40
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What is the main limitation of using scatterplots? |
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Card: 38 / 40
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The main limitation of scatterplots is that they can only show the relationship between two variables at a time. More complex relationships involving multiple variables cannot be effectively visualized with a scatterplot. |
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Card: 39 / 40
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If a scatterplot shows a cluster of points in the upper left and lower right quadrants, what type of correlation does it indicate? |
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Card: 40 / 40
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This pattern indicates a negative correlation, as points in the upper left suggest decreasing values while points in the lower right suggest increasing values. |
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 Completed! Keep practicing to master all of them. |
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