A zoologist collected wild lizards in the Southwestern United States. Thirty lizards from the genus Phrynosoma were placed on a treadmill, and their speed was measured. The recorded speed (meters/second) is the fastest time to run a half meter.

1.28, 1.36, 1.24, 2.47, 1.94, 2.52, 2.67, 1.29,
1.56, 2.66, 2.17, 1.57, 2.10, 2.54, 1.63, 2.11,
2.57, 1.72, 0.76, 1.02, 1.78, 0.50, 1.49, 1.57,
1.04, 1.92, 1.55, 1.78, 1.70, 1.20

Find the sample median, first quartile, and third quartile.

Thus the sample median, first quartile, and third quartile of a set of speeds recorded from lizards in the study is 1.665 m/s., 1.245 m/s, and 2.355 m/s. respectively

The sample median: First, we need to arrange the speeds in ascending order: 0.50, 0.76, 1.02, 1.04, 1.20, 1.24, 1.28, 1.29, 1.36, 1.49, 1.55, 1.56, 1.57, 1.57, 1.63, 1.70, 1.72, 1.78, 1.78, 1.92, 1.94, 2.10, 2.11, 2.17, 2.47, 2.52, 2.54, 2.57, 2.66, 2.67.

To find the median, since we have 30 data points, the median will be the average of the 15th and 16th values, which are 1.63 and 1.70. Thus, the median speed is 1.665 m/s.

The first quartile (Q1): To find Q1, we need to identify the median of the lower half of the data. Q1 is the median of the speeds from 0.50 to 1.57, which gives Q1 as 1.245 m/s.

The third quartile (Q3): Q3 is the median of the upper half of the data. So, from 1.78 to 2.67, the median is Q3 as 2.355 m/s.