Scatterplots

Front

What is a scatterplot?

Back

A scatterplot is a graphical representation of two variables, where each point represents an observation in the dataset, allowing for the visualization of relationships between the variables.

Front

What does a negative correlation in a scatterplot indicate?

Back

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

Front

How can you estimate values using a trend line in a scatterplot?

Back

You can estimate values by locating the point on the trend line that corresponds to the value of interest and reading the associated value on the other axis.

Front

What is the purpose of a trend line in a scatterplot?

Back

A trend line is used to summarize the relationship between the variables and to make predictions based on the data.

Front

What does it mean if a scatterplot shows no correlation?

Back

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

Front

How do you determine the slope of a trend line in a scatterplot?

Back

The slope of a trend line is determined by the change in the y-values divided by the change in the x-values between two points on the line.

Front

What is the significance of outliers in a scatterplot?

Back

Outliers are data points that fall far from the trend line and can significantly affect the correlation and slope of the trend line.

Front

How can scatterplots be used in real-world applications?

Back

Scatterplots can be used in various fields such as economics, biology, and social sciences to analyze relationships between variables and make predictions.

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 data points.

Front

What does a correlation coefficient of -1 indicate?

Back

A correlation coefficient of -1 indicates a perfect negative linear relationship between two variables.