What does kurtosis mean in Stata?

Kurtosis – Kurtosis is a measure of the heaviness of the tails of a distribution. A normal distribution has a kurtosis of 3. Heavy tailed distributions will have kurtosis greater than 3 and light tailed distributions will have kurtosis less than 3.

What is Sktest Stata?

Description. For each variable in varlist, sktest presents a test for normality based on skewness and another based on kurtosis and then combines the two tests into an overall test statistic. sktest requires a minimum of eight observations to make its calculations.

What does valid N Listwise mean?

Note that “Valid N (listwise)” denotes the number of cases that don’t have any missing values on any of the variables shown in the table.

How do you test for kurtosis?

The normal distribution has a skewness of zero and kurtosis of three. The test is based on the difference between the data’s skewness and zero and the data’s kurtosis and three. The test rejects the hypothesis of normality when the p-value is less than or equal to 0.05.

How do you interpret data in descriptive statistics?

Interpret the key results for Descriptive Statistics

1. Step 1: Describe the size of your sample.
2. Step 2: Describe the center of your data.
3. Step 3: Describe the spread of your data.
4. Step 4: Assess the shape and spread of your data distribution.
5. Compare data from different groups.

How do you get n in SPSS?

In the Summary Statistics dialog box, select Count in the Statistics list and click the arrow to add it to the Display list. Then select Valid N in the Statistics list and click the arrow to add it to the Display list.

What is a good kurtosis value?

A standard normal distribution has kurtosis of 3 and is recognized as mesokurtic. An increased kurtosis (>3) can be visualized as a thin “bell” with a high peak whereas a decreased kurtosis corresponds to a broadening of the peak and “thickening” of the tails. Kurtosis >3 is recognized as leptokurtic and <3.

What is the kurtosis of a normal distribution?

In SAS, a normal distribution has kurtosis 0. Extremely nonnormal distributions may have high positive or negative kurtosis values, while nearly normal distributions will have kurtosis values close to 0.

What does kurtosis mean in SAS?

k. Kurtosis – Kurtosis is a measure of the heaviness of the tails of a distribution. In SAS, a normal distribution has kurtosis 0. Extremely nonnormal distributions may have high positive or negative kurtosis values, while nearly normal distributions will have kurtosis values close to 0.

What is skewness and kurtosis?

Skewness – Skewness measures the degree and direction of asymmetry. A symmetric distribution such as a normal distribution has a skewness of 0, and a distribution that is skewed to the left, e.g., when the mean is less than the median, has a negative skewness. n. Kurtosis – Kurtosis is a measure of the heaviness of the tails of a distribution.

How do I use weights in Stata?

In Stata, you can use different kinds of weights on your data. By default, each case (i.e., subject) is given a weight of 1. When this default is used, the sum of the weights will equal the number of observations. c. Mean – This is the arithmetic mean across the observations.