2k views

### Interpretation of qq plot and normality [duplicate]

I am doing some multivariate regression. When I plot QQnorms to check my model assumptions (errors normally distributed), I get Question: How do you interpret the above? Are the normality assumptions ...
219 views

### How can I visually determine the normality of interval data through a Q-Q Plot? [duplicate]

When dealing with interval data coming from questionnaires using Likert-Scales, I want to be able to determine the normality of the data in question. Some of the answers here on Cross Validated have ...
268 views

### What does this QQplot tell us? [duplicate]

For a multivariate data set, I test normality on the marginals, and I get plots like above. That's not my actual plot.... mine is not that obvious, the middle part is actually quite straight.... but ...
54 views

### How to verify assumptions of a normal distribution? [duplicate]

I'm working with the iris data.I made a density plot And a qq plot For sepal Length.It looks Approximately normal With the left skew And a flat peak The points In the qq Plot Stay within The ...
37 views

### Fail normality test but the qqplot is a straight line [duplicate]

I am using SAS 9.4 . My aim is to find out whether my residual is normal or not, so i type this: ...
262k views

### How to interpret a QQ plot

I am working with a small dataset (21 observations) and have the following normal QQ plot in R: Seeing that the plot does not support normality, what could I infer about the underlying distribution? ...
5k views

### What is the relationship between $Y$ and $X$ in this plot?

What is the relationship between $Y$ and $X$ in the following plot? In my view there is negative linear relationship, But because we have a lot of outliers, the relationship is very weak. Am I right? ...
27k views

### How to draw fitted graph and actual graph of gamma distribution in one plot?

Load the package needed. library(ggplot2) library(MASS) Generate 10,000 numbers fitted to gamma distribution. ...
2k views

### Formal definition of the qqline used in a Q-Q plot

I'm doing some distribution fitting work and I'm looking at Q-Q plots and how they can be used visually to interpret goodness of fit. My data is heavy-tailed so I am looking at Weibull, log-normal, ...
656 views

### Interpretation of QQ-plots

I've read what they mean on a technical level, but I'm trying to build intuition related to a specific problem. So I have some data, a set of measurements. It's pretty curvy, looking like a cross ...
652 views

### Using MLE to determine parameters for QQ plot

I just started playing around with a credit fraud dataset that I found online. I noticed that one of the variables looked something like this: Hey, that looks like a 3 parameter log-normal ...
821 views

### QQ Plot - drawn from a normal distribution?

I want to compare the distribution of the data from my model with normal distribution (since some previous works state that in comparison with normal dist. my data should have thicker tails). I ...
237 views

### Normal Probability Plot: oscillation around straight line: polynomial relationship?

This is the Normal Probability Plot I've obtained for some data: As you can see the points seem to osciallate, as in a period, around the line of slope 1 and passing through the origin. I've obtained ...