Question

(a) fill in the blank. to find the lower quartile, find the of the lower half of the data set. (b) fill in the blank. to find the, find the upper half of the data set.

Explanation:

(a) The lower quartile (Q1) is defined as the middle value (median) of the lower half of a sorted data set.
(b) The upper quartile (Q3) is defined as the median of the upper half of a sorted data set, which matches the structure of the blank.

Answer:

(a) median
(b) upper quartile; median