There isn't any immediate process choice for calculating the KR21, and that is determined by the (usually unrealistic) assumption that all products in the size have equal trouble degrees (i.e. equal proportions of 'successes' to the products). The KR21 may be calculated in SPSS by utilizing the Mixture A single https://what-is-kr-2027161.blogolize.com/a-review-of-kr-20-66120191