a researcher wants to determine the impact of soil type on the

 A researcher wants to determine the impact of soil type on the growth of a certain type of plant. She grows three plants in each of four different types of soil and measures the growth in inches for each plant after one month resulting in the data below.

11
13
10.1
12.8
12.3
9.5
8.2
12.5
11.4
11.9
7.9
12.5