Register a new set of midpoints of the grouped data set.
k
-th element is the midpoint of the k
-th grouping.Note that with the grouped data approach we will implicitly assume that the `mean' of the data set elements within a given collection corresponding to an sub-interval of the real line is the midpoint of the interval considered. Though in most cases this will not be precisely true, the midpoint will be approximately equal to the mean of the set of elements within the interval.
If we grouped the data consisting of the heights of a collection of
people in accordance with the intervals: 0
m - 1.20
m,
1.21
m - 1.50
m, 1.51
m - 2.00
m,
2.01
m - 3
m. Then the corresponding mid-points are:
0.60
m, 1.25
m, 1.75
m and 2.50
m;
which is passed to this method and set to the private field by passing the
array {0.60, 1.25, 1.75, 2.50}
.
GroupedData Class | Statistics Namespace