Each gust of the clouded mood that seemed warmed by the heat of a heart flaming with anger has its counterpart in the chilly blasts that seem blown from a breast turned to ice with a sudden revulsion of feeling.
The dimension is the number of bases in the COLUMN SPACE of the matrix representing a linear function between two spaces. i.e. if you have a linear function mapping R3 --> R2 then the column space of the matrix representing this function will have dimension 2 and the nullity will be 1.
In fact even in mathematics there are different averages or means and this one is more properly called the arithmetic mean. The quantity obtained by adding the largest and smallest values and dividing by 2, statisticians call the midrange. There are times however that this is called the mean.