To investigate whether light affects root growth when stems

To investigate whether light affects root growth (when stems have been cut during growth), a t-test is to be performed on the measurements that you made. State the null and alternative hypotheses of this test.

Lengths of roots (in mm) obtained in a mustard seedlings experiment measurements given in bold type were obtained from seedlings whose stems were cut during their growth. A cross indicates a seed that did not germinate.

Solution

Null Hypothesis: light is not affects root growth

Alternative Hypothesis:  light is not affects root growth