- #1
nomadreid
Gold Member
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I am confused by the labeling of the (only) graph in
http://en.wikipedia.org/wiki/Pearson's_chi-squared_test
The values on the vertical axis appear to be the values of 1-(the chi-squared cumulative probability distribution values*)
as I would expect in finding the p-values.
However, this graph is labeled the "chi-squared distribution" -- which is ambiguous enough, but when one clicks on this term under the graph, one is directed to a site where the term means the chi-squared probability density function. But the graph cannot be the probability density function: the values are different*, and a probability density function has probability densities on the vertical axis, not probabilities.
So, is this mislabeled?
(*The pdf and cdf graphs were taken from http://en.wikipedia.org/wiki/Chi-squared_distribution#Probability_density_function, and individual values, for more precision, from http://www.danielsoper.com/statcalc3/calc.aspx?id=11)
http://en.wikipedia.org/wiki/Pearson's_chi-squared_test
The values on the vertical axis appear to be the values of 1-(the chi-squared cumulative probability distribution values*)
as I would expect in finding the p-values.
However, this graph is labeled the "chi-squared distribution" -- which is ambiguous enough, but when one clicks on this term under the graph, one is directed to a site where the term means the chi-squared probability density function. But the graph cannot be the probability density function: the values are different*, and a probability density function has probability densities on the vertical axis, not probabilities.
So, is this mislabeled?
(*The pdf and cdf graphs were taken from http://en.wikipedia.org/wiki/Chi-squared_distribution#Probability_density_function, and individual values, for more precision, from http://www.danielsoper.com/statcalc3/calc.aspx?id=11)