The least and greatest values in data set $$X$$ are $$j$$ and $$k$$. respectively, and the least and greatest values in data set $$Y$$ are $$p$$ and $$r$$, respectively, where $$j < k < p < r$$. The least value in data set $$Z$$ is the average (arithmetic mean) of $$j$$ and $$k$$, and the greatest value in data set $$Z$$ is the average of $$p$$ and $$r$$.
Quantity A
The average of the range of the values in data set $$X$$ and the range of the values in data set $$Y$$
Quantity B
The range of the values in data set $$Z$$