The number of groups (generally between 5- 12) is calculated by dividing the difference between the maximum value and the minimum value by the group distance. It is necessary to determine whether the group distance is appropriate to ensure that the data will not fall on the boundary value of two adjacent groups, resulting in statistical errors.
2, the group spacing is 5 to12; The number of groups is 8.
(max-min) ÷ group distance = number of groups, so, (99-60)÷5= seven and four fifths (that is, eight), so the number of groups is eight.
The quotient of the maximum minus the minimum divided by the group distance must be in the range of 5 to 12 groups.
Extended data
Group spacing and grouping principle
The principle of "no weight and no leakage" should be followed when grouping according to the group distance. "Not heavy" means that a piece of data can only be divided into one group and cannot be repeated in other groups; "No leakage" means that groups can be exhausted, that is, in all groups, each data can be divided into a group and cannot be omitted. ?
In order to solve the problem of "no weight", it is customary to stipulate that "the upper limit of the group is not included" in statistical grouping, that is, when the upper and lower limits of two adjacent groups overlap, the variable value exactly equal to the upper limit of one group is not included in this group, but included in the next group.
The group spacing is not necessarily an integer, but it is usually an integer for the convenience of grouping. The number of groups must be an integer.
Baidu Encyclopedia-Group Distance
Baidu encyclopedia-group number