Q1) Psychologist would like to study effects of new drug on activity level of animals. 3 samples of rats are chosen with n = 5 in each sample. One group gets no drug, one group gets small dose, and third group gets a large dose. Psychologist records activity level for each animal. Data from this experiment are presented below.
|
No drug
|
Small dose
|
Large dose
|
|
|
5
|
5
|
10
|
|
|
3
|
5
|
12
|
|
|
1
|
9
|
9
|
G = 90
|
|
1
|
6
|
6
|
ΣX2 = 678
|
|
5
|
5
|
8
|
|
|
T = 15
|
T = 30
|
T = 45
|
|
|
SS = 16
|
SS = 12
|
SS = 20
|
|
a) Do these data point to any significant differences among three groups? Test with α = .05.-----------------and conclude that drug------------- a significant effect on activity level.
b) Calculate η2, the percentage of variance accounted for by treatment.