Todos Logos posted an article on Statistic on aiR - Sep 5, 2009, 1:26 pm
Suppose we want to create a polynomial that can approximate better the following dataset on the population of a certain Italian city over 10 years. The table summarizes the data: $$\begin{tabular}{|1...
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Todos Logos posted an article on Statistic on aiR - Aug 25, 2009, 1:44 pm
This post is a summary of my two previous posts on the trend analysis with the Cox-Stuart test and on simple linear regression. The goal that we propose is to assess the trend in the number of visits ...
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Todos Logos posted an article on Statistic on aiR - Aug 20, 2009, 5:43 am
In this post we will see briefly how to implement a logistic regression model if you have categorical variables, or qualitative, organized in double entry contingency tables. In this model the depende...
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Todos Logos posted an article on Statistic on aiR - Aug 8, 2009, 2:59 am
The Cox-Stuart test is defined as a little powerful test (power equal to 0.78), but very robust for the trend analysis. It is therefore applicable to a wide variety of situations, to get an idea of th...
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Todos Logos posted an article on Statistic on aiR - Aug 7, 2009, 1:28 pm
The one-way analysis of variance is a useful technique to verify if the means of more groups are equals. But this analysis may not be very useful for more complex problems. For example, it may be nece...
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Todos Logos posted an article on Statistic on aiR - Aug 6, 2009, 12:30 am
We use the regression analysis when, from the data sample, we want to derive a statistical model that predicts the values of a variable (Y, dependent) from the values of another variable (X, independe...
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Todos Logos posted an article on Statistic on aiR - Aug 5, 2009, 12:30 am
If you have qualitative variable, it is possible to verify the correlation by studying a contingency table R by C, using the Pearson's Chi-squared test. A casino wants to study the correlation be...
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Todos Logos posted an article on Statistic on aiR - Aug 4, 2009, 12:30 am
We saw in the previous post, how to study the correlation between variables that follow a Gaussian distribution with the Pearson product-moment correlation coefficient. If it is not possible to assum...
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Todos Logos posted an article on Statistic on aiR - Aug 3, 2009, 2:33 am
Suppose you want to study whether there is a correlation between 2 sets of data. To do this we compute the Pearson product-moment correlation coefficient, which is a measure of the correlation (linear...
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Todos Logos posted an article on Statistic on aiR - Jul 31, 2009, 3:46 am
If you have to perform the comparison between multiple groups, but you can not run a ANOVA for multiple comparisons because the groups do not follow a normal distribution, you can use the Kruskal-Wall...
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Todos Logos posted an article on Statistic on aiR - Jul 30, 2009, 2:32 am

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