Scatter Plots and Predictions

Front

What is a scatter plot?

Back

A scatter plot is a graphical representation of two variables, showing the relationship between them using points on a Cartesian plane.

Front

What does a negative correlation indicate in a scatter plot?

Back

A negative correlation indicates that as one variable increases, the other variable tends to decrease.

Front

What does a positive correlation indicate in a scatter plot?

Back

A positive correlation indicates that as one variable increases, the other variable also tends to increase.

Front

What does no correlation mean in the context of a scatter plot?

Back

No correlation means there is no discernible relationship between the two variables; changes in one variable do not predict changes in the other.

Front

How can you predict values using a trend line in a scatter plot?

Back

You can predict values by extending the trend line and finding where it intersects with the value of interest on the axis.

Front

What is the purpose of a trend line in a scatter plot?

Back

A trend line summarizes the relationship between the variables and helps in making predictions based on the data.

Front

What is the formula for calculating the correlation coefficient (r)?

Back

The correlation coefficient (r) is calculated using the formula: r = (nΣxy - ΣxΣy) / sqrt[(nΣx^2 - (Σx)^2)(nΣy^2 - (Σy)^2)], where n is the number of pairs.

Front

What does the slope of a trend line represent in a scatter plot?

Back

The slope of a trend line represents the rate of change between the two variables; it indicates how much one variable changes for a unit change in the other.

Front

What is the significance of outliers in a scatter plot?

Back

Outliers are data points that deviate significantly from the trend of the rest of the data; they can affect the correlation and predictions.

Front

How do you interpret the y-intercept of a trend line?

Back

The y-intercept of a trend line is the value of the dependent variable when the independent variable is zero.