The mathematical modeling function of SPSS is summarized as follows:

1, in the basic statistical analysis function of spss, there is a frequency histogram of each observed value of a variable, and you can choose to draw a normal curve. The details are as follows: Analysis-Descriptive Statistics-Frequency. Open the dialog box of frequency statistics, and you can choose to obtain various descriptive statistics, such as mean, variance, quantile, kurtosis, standard deviation and so on. In the chart, you can choose the type of graph to display, and the histogram option is histogram, which is what we call histogram. At the same time, you can choose whether to draw this set of data with norma curve, so that we can intuitively observe whether this set of data roughly conforms to the normal distribution. 2. q-q diagram of normal distribution: In the exploratory analysis of the basic statistical analysis function of spss, we can judge whether the data obeys normal distribution by observing the Q-Q diagram of the data.

The specific steps are as follows: Analyze-Descriptive Statistics-Explore to open the dialog box, select the Plots option, select the option of normal distribution with test, and draw the q-q diagram of this group of data. The abscissa of the chart is the observed value of change, and the ordinate is the quantile. If this set of data obeys normal distribution, then the points in the graph should be close to the straight lines in the graph. The ordinate is the quantile, which is obtained according to the distribution function formula F(x)=i/n+ 1. I is the position of the ith data after a group of numbers are sorted from small to large, and n is the sample size. If the array obeys normal distribution, its q-q diagram should be basically consistent with the theoretical q-q diagram (that is, the straight line in the diagram). For the theoretical standard normal distribution, its q-q diagram is y=x straight line. The slope of nonstandard normal distribution is the sample standard deviation and the intercept is the sample mean.