An entomologist conducted an experiment to see if wounding a tomato plant would induce changes that improve its defense against insect attack. She grew larvae of the tobacco hornworm (Manduca sexta) on wounded plants or control plants. The accompanying table shows the weights (mg) of the larvae after seven days of growth.39 (Assume that the data are normally distributed.) How strongly do the data support the researcher's expectation? Use a test at the 5% significance level. Let HA be that wounding the plant tends to diminish larval growth.
|
WOUNDED |
CONTROL |
N |
16 |
18 |
Y- |
28.66 |
37.96 |
S |
9.02 |
11.14 |