(1) difference coefficient method; Dispersion is expressed by the coefficient of difference, CV= s/X (where CV represents the coefficient of difference, s represents the standard deviation of the sample and x represents the average value of the sample), cv1= 0.7/1.3 = 0.533, CV2= 1.2/4.3=0.273.

Obviously CV2.

At present, there is no statistical inference of the coefficient of difference CV, and there is no effective hypothesis testing method so far, so there is no significant level.

(2) standard score law; Z=(x-X)/s (where x represents the original value, x represents the average value and s represents the standard deviation).

Z 1=5.24，Z2=4.75。 z 1 & gt； Z2, so the dispersion of 5cm is relatively large.

Both methods reflect the deviation of two groups of mean values. Z score is of great significance to statistics.

Reference: Zhang Houcan's Modern Psychology and Education Statistics, pp. 94-96.