Final answer:
The lower quartile, or first quartile (Q₁), for the given data set is 29.4.
Step-by-step explanation:
To find the lower quartile, or first quartile (Q₁), we need to arrange the data set in ascending order:
5.8, 9, 13.2, 17.4, 29.4, 30.8, 33.8, 40.4, 43, 47.2, 50.6, 51.6, 61.4, 62, 64.2, 68.2
Since there are 16 values, the lower half consists of the first 8 values. The median of the lower half is the first quartile. In this case, the first quartile is 29.4.