Correlation and Association Concepts

Front

What is correlation in statistics?

Back

Correlation is a statistical measure that describes the extent to which two variables change together. A positive correlation means that as one variable increases, the other also increases, while a negative correlation means that as one variable increases, the other decreases.

Front

What does a scatter plot represent?

Back

A scatter plot is a graphical representation of two variables, showing the relationship between them. Each point on the plot represents an ordered pair of values.

Front

What does it mean if a scatter plot shows no correlation?

Back

If a scatter plot shows no correlation, it means that there is no predictable pattern between the two variables; changes in one variable do not affect the other.

Front

Define positive correlation with an example.

Back

Positive correlation occurs when two variables move in the same direction. For example, as the temperature increases, ice cream sales tend to increase.

Front

Define negative correlation with an example.

Back

Negative correlation occurs when two variables move in opposite directions. For example, as the number of hours spent watching TV increases, grades in school may decrease.

Front

What is a trend line in a scatter plot?

Back

A trend line is a straight line that best represents the data points in a scatter plot, indicating the general direction of the relationship between the variables.

Front

How can you use a trend line to make predictions?

Back

You can use a trend line to predict the value of one variable based on the value of another by extending the line and finding the corresponding point.

Front

What is the formula for finding the slope of a line?

Back

The slope (m) of a line is calculated using the formula m = (y2 - y1) / (x2 - x1), where (x1, y1) and (x2, y2) are two points on the line.

Front

What is the significance of the y-intercept in a linear equation?

Back

The y-intercept is the point where the line crosses the y-axis, representing the value of y when x is zero.

Front

What does it mean if a scatter plot has a strong correlation?

Back

A strong correlation in a scatter plot means that the data points are closely clustered around the trend line, indicating a strong relationship between the two variables.