Scatter Plots - SAT Math
- What does a residual plot show?
- The residuals on the y-axis versus the independent variable. Helps assess whether the linear model fits the data well.
- Choose the correlation: Slope is negative.
- Negative correlation. Negative slope means variables move in opposite directions.
- What does each point on a scatter plot represent?
- A pair of values for the two variables being compared. One coordinate from each variable creates a single data point.
- Find the pattern: Residuals show no clear pattern.
- The model is appropriate for the data. Random residuals suggest the linear model is valid.
- What does clustering in a scatter plot indicate?
- Groups of data points clustered together. Shows distinct groups or categories within the data set.
- Find the strength: Correlation coefficient is -0.2.
- Weak negative correlation. is close to , indicating a weak relationship.
- What is the line of best fit?
- A straight line that best represents the data on a scatter plot. Also called a trend line, it summarizes the data's relationship.
- What is the role of the correlation coefficient?
- To quantify the strength and direction of a relationship. Measures how closely the data follows a linear pattern.
- What does a correlation coefficient of 1 indicate?
- Perfect positive linear relationship. All points lie exactly on an upward-sloping line.
- Identify the type of prediction: Beyond data range.
- Extrapolation. Predicting outside the data range carries more uncertainty.
- What does no correlation look like on a scatter plot?
- Points are scattered randomly with no clear trend. No predictable pattern exists between the two variables.
- What is a scatter plot used for in data analysis?
- To visualize the relationship between two quantitative variables. Shows how one variable changes as another changes.
- Identify the variable type: x-axis in a scatter plot.
- Independent variable. The x-axis variable is controlled or chosen first.
- Find the strength: Correlation coefficient is 0.85.
- Strong positive correlation. is close to , indicating a strong positive relationship.
- What information does the slope of the trend line give?
- The rate of change between the variables. Slope shows how much y changes per unit increase in x.
- What is indicated by outliers in a scatter plot?
- Data points that deviate significantly from the pattern. These unusual points don't follow the overall trend.
- What is interpolation in the context of scatter plots?
- Predicting values within the range of the data. Uses the trend line between existing data points.
- Identify the type of prediction: Within data range.
- Interpolation. Predicting between existing points is generally more reliable.
- Identify the x-axis on a scatter plot.
- The horizontal axis representing the independent variable. Also called the independent variable because it's controlled or measured first.
- Identify the variable type: y-axis in a scatter plot.
- Dependent variable. The y-axis variable responds to changes in the x-variable.
- Which term describes a pattern where points form a straight line?
- Linear relationship. Points can be approximated by a straight line.
- Which type of correlation is suggested by a downward trend in a scatter plot?
- Negative correlation. Downward slope indicates variables move in opposite directions.
- What is a scatter plot?
- A graph that shows the relationship between two variables using points. Each point plots one x-value against one y-value to visualize patterns.
- Identify the type of correlation: points slope downward.
- Negative correlation. As one variable increases, the other decreases.
- Find the strength: Correlation coefficient is 0.
- No correlation. Zero means no linear relationship exists between the variables.
- What is extrapolation in the context of scatter plots?
- Predicting values outside the range of the data. Extends the trend line beyond the given data points.
- What is a bivariate relationship?
- A relationship involving two variables. Scatter plots specifically examine two-variable relationships.
- What does a positive correlation in a scatter plot indicate?
- As one variable increases, the other variable also increases. Both variables move in the same direction together.
- What is the primary purpose of a scatter plot?
- To display the relationship between two quantitative variables. Shows how two numerical variables relate or change together.
- What does a correlation coefficient of -1 indicate?
- Perfect negative linear relationship. All points lie exactly on a downward-sloping line.
- What is the purpose of a trend line in a scatter plot?
- To show the general direction or pattern of the data. Helps visualize the overall relationship and make predictions.
- Choose the correct term: Relationship measured by 'r' value.
- Correlation coefficient. The value measures strength and direction of correlation.
- Choose the correlation: Slope is zero.
- No correlation. Zero slope means y doesn't change as x changes.
- Find the correlation: Points trend upwards.
- Positive correlation. Upward trend indicates both variables increase together.
- Find and correct the error: Points tightly clustered indicate weak correlation.
- Correct: indicate strong correlation. Tightly clustered points show strong, not weak correlation.
- What is a residual in a scatter plot?
- The difference between observed and predicted values. Measures how far each point deviates from the trend line.
- Find the correlation: Points are scattered randomly.
- No correlation. Random scatter indicates no predictable relationship between variables.
- What does a correlation coefficient of 0 indicate?
- No linear relationship. Variables are not linearly related to each other.
- What does a steep slope indicate in a scatter plot?
- A strong relationship between the variables. Large changes in y correspond to small changes in x.
- Identify the y-axis on a scatter plot.
- The vertical axis representing the dependent variable. Also called the dependent variable because it responds to changes in x.
- Determine the correlation: points form a U-shape.
- Non-linear relationship. The relationship follows a curved pattern, not a line.
- Choose the correlation: Slope is positive.
- Positive correlation. Positive slope means both variables increase together.
- Identify the tool used to draw a line of best fit.
- Linear regression. Method that creates the best-fitting line through data points.
- Given a scatter plot with no discernible pattern, what is the correlation type?
- No correlation. Random scatter with no clear pattern means variables are unrelated.
- What does a shallow slope indicate in a scatter plot?
- A weak relationship between the variables. Small changes in y correspond to changes in x.
- How is the line of best fit determined?
- By minimizing the distances from all points to the line. Uses least squares method to minimize total squared distances.
- What does a negative correlation look like on a scatter plot?
- Points trend downwards from left to right. As x increases, y decreases, showing an inverse relationship.
- What is the role of outliers in a scatter plot?
- Outliers are data points that deviate significantly from the trend. They can affect trend lines and correlation strength significantly.
- Identify an outlier in a scatter plot.
- A point that lies far from the general pattern of the data. Look for points that don't follow the main cluster or trend.
- Find the correlation: Points trend downwards.
- Negative correlation. Downward trend indicates one variable decreases as the other increases.
- What is the range of the correlation coefficient?
- From -1 to 1. Values closer to indicate stronger linear relationships.
- What does it mean if a scatter plot shows no discernible pattern?
- No correlation. The variables are not related in a predictable way.
- What does a positive correlation look like on a scatter plot?
- Points trend upwards from left to right. As x increases, y also increases, showing a positive relationship.
- Identify the type of correlation: points slope upward.
- Positive correlation. As one variable increases, the other also increases.
- Identify the line that best represents the trend in a scatter plot.
- Line of best fit (or trend line). Drawn through data points to show the overall pattern or trend.