Central tendency refers to the degree to which a set of data moves closer to a certain central value. It reflects the degree to which a set of data moves closer to a certain central value. It reflects the location of the center point of a set of data. Common variables that represent central tendency include median and mean. Dispersion trend indicators generally describe trends away from their central values. Common indicators indicating the degree of dispersion include variance or standard deviation, coefficient of variation, etc. The shape of the distribution generally reflects the skewness (skewness) and kurtosis (kurtosis) of the data distribution. If you want to get the central tendency index, the discrete trend index and the shape of the distribution of the waist circumferences of these 15 college students, you can perform formula calculations, or Use software to get it quickly.

Calculation of indicators of central tendency

There are many indicators that indicate the central tendency of a set of data. Here we describe the mean and median.

Mean

Mean is the result of adding a set of data and dividing it by the number of data. The mean is the most important measure of central tendency. It is mainly suitable for quantitative data. It is not suitable for categorical data. The calculation formula is as follows:

So the mean of the case is:

Median

The median is the variable in the middle position after a set of data is sorted value, if you want to get the median waist circumference of 15 college students, you need to sort the data first and find the value in the middle. After sorting, the median is 73.5.