1 This is chi-square test, and k 2 tests the relationship between the two groups. The greater the value, the greater the relationship. First of all, the two are related. Look-up table can only know that the p value is between 0.0 1-0.00 1, greater than 1% and less than 0. 1%, that is, the statistical significance is above 99%. A should not exceed 1%.

2 the second red circle, because the other four days are identified as four questions, then choose one more and one less from the six days, namely C 16 and C 15. Multiplying by A33 is even more wrong, so it is wrong to fix four questions together for four days.

Regarding the need for average grouping, this topic has been changed, because it involves time sequence, so there is no need to divide. If no sequence is involved, averaging is needed. For example, if you want two of six people, one chooses three topics and the other chooses five topics, you need to divide by A22.