t-test of the Dandelion Data

In this activitiy, you will be performing a t-test on the dandelion data to determine whether or not there is a significant difference between the peduncle (stem) length of dandelions that were grown in different environments. The experiment was founded on the assumption that there would be basic differences between both the root and stem systems of plants that developed with different environmental stressors.

The sample dandelion plants were taken from two test sites; one site was located in a regularly mowed lawn, and the other in an untouched grassy field. It is known that all plants have some sort of adaptive behavior so as to be better suited for the environment in which they live. Would the dandelion plants also make the adaptations that would help to ensure future growth and development of the population? Using either Excel or the TI-83 graphing calculator, perform a t-test to determine if there is a significant difference between the peduncle length of plants cultivated in the lawn and field environments.

This data exists in three files; one is in Excel Data format, one is in Text format, and one is in TI-83 Group format. If you want to perform the t-test using the TI-83, you will have to import the text data into the calculator from the computer after you have downloaded the file.

Was there a significant difference in the peduncle lengths of the two sets of dandelion plants? How comparable are the means of the two groups? Were the results what you had expected from this experiment? What are some possible factors that could have influenced the growth characteristics of these two sets of the same plant? Are they all environmental?