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What else can I help you with?
How do you know if a scatter plot has a strong correlation?
You can look at the r value and tell from there. Also you can try to see if there is a linear assocation and if its tightly centered or loosely centered.
What does Pearson's linear correlation coefficient measure?
Strength and direction of linear relation. Closer to 1 is positive linear association, closer to -1 is positive negative association and closer to 0 means no linear relation. Remember that 0 does not mean that there is no relation - just no linear relation.
What graphs can you use to find the strength of correlation between two continuous data sets that isn't a scatter graph?
You cannot. Or rather, you should not. You do not know if the relationship is linear or something else. A scatter graph is the best way to establish the nature of the relationship. For example, the correlation between x and y, when y = x2 between, say, -4 and +4 is zero (because of symmetry). That would lead you to conclude that there was no relationship. You could not be more incorrect!
What does a correlation near 1 or -1 indicate?
The closer the correlation is to 1 or -1, the more linear the data is
What measures the strength of the linear relationship between two quantitative variables?
The coefficient of determination, otherwise known as the r^2 value, measures the strength of the linear relationship between two quantitative variables. An r^2 value of 1 indicates a complete linear relationship while a value of 0 means there is no relationship.
What is the range of correlation coefficient and what does its value tell?
The product-moment correlation coefficient or PMCC should have a value between -1 and 1. A positive value shows a positive linear correlation, and a negative value shows a negative linear correlation. At zero, there is no linear correlation, and the correlation becomes stronger as the value moves further from 0.
Difference between positive and negative correlation?
If the two variables increase together and decrease together AND in a linear fashion, the correlation is positive. If one increases when the other decreases, again, in a linear fashion, the correlation is negative.
What is a large but not perfect positive linear correlation?
men and penises
Is it possible to make a prediction based in a scatter plot with no correlation?
Correlation is an estimate of a linear relationship between two variables and takes no account of non-linear relationship. If the relationship is quadratic and the domain is symmetric about some point, the correlation will be zero. It is, thus possible for the points on the scatter plot to lie exactly on a parabola while the calculated correlation is zero. In such a case, it is easy to make a prediction despite no correlation.
How do you read a scatter graph?
Scatter-plot shows correlation between two different variables (one on the y-axis, the other on x-axis). If there is linear correlation, the scatter-points form a straight line from zero (origo) to some direction. The more cloud-like distribution the scatter-plot does have, the less those variables in question have correlation or dependence with each other.
Does a scatter plot have a linear relationship?
A scatter plot can show a linear relationship between two variables if the points tend to cluster around a straight line. However, not all scatter plots exhibit linear relationships; they can also display nonlinear patterns or no discernible relationship at all. To determine if a linear relationship exists, one can visually inspect the plot or calculate the correlation coefficient.
What is the data telling you with a positive or negative correlation?
If the data have a positive or negative correlation, it means the data have a linear relationship in the form of an equation of a line; or Y = mX + b.
Is the slope of a line positive when doing linear regression if the correlation coefficient is negative?
No, the slope of a line in linear regression cannot be positive if the correlation coefficient is negative. The correlation coefficient measures the strength and direction of a linear relationship between two variables; a negative value indicates that as one variable increases, the other decreases. Consequently, a negative correlation will result in a negative slope for the regression line.
When doing linear regression if the correlation coefficient is positive the slope of the line is negative?
False.
Is it possible for the correlation and the slope to have opposite signs?
No, it is not possible for the correlation and the slope to have opposite signs in a linear regression context. The correlation coefficient indicates the direction and strength of a linear relationship between two variables, while the slope represents the change in the dependent variable for a unit change in the independent variable. If the correlation is positive, the slope will also be positive; if the correlation is negative, the slope will likewise be negative.
Does a good correlation have to be positive?
No. If the correlation coefficient is close to 1 or -1, then the two variables have a high degree of statistical linear correlation. See the related link, particularly the graphs which illustrate correlation.
How do you know if a scatter plot has a strong correlation?
You can look at the r value and tell from there. Also you can try to see if there is a linear assocation and if its tightly centered or loosely centered.
