Question

A research psychologist wishes to investigate the difference in maze test scores for a strain of laboratory mice trained under different laboratory conditions. The experiment is conducted using 18 randomly selected mice of this strain, with six receiving no training at all (control group), six trained under condition 1, and six trained under condition 2. Then each of the mice is given a test score between 0 and 10, depending on its performance in a test maze. A higher score is better performance. The experiment produced the results in the table.

     Control             Condition 1         Condition 2

     5.8                 7.3                 5.3

     3.2                 7.0                 7.4

     5.9                 6.8                 7.2

     6.4                 7.1                 6.2

     5.5                 6.0                 5.8

     4.9                 6.2                 6.1

Answer 1

The hypothesis being tested is:

H0: µ1 = µ2 = µ3

Ha: Not all means are equal

	Mean	n	Std. Dev
	5.28	6	1.134	Control
	6.73	6	0.520	Condition 1
	6.33	6	0.814	Condition 2
	6.12	18	1.024	Total
ANOVA table
Source	SS	df	MS	F	p-value
Treatment	6.730	2	3.3650	4.55	.0286
Error	11.095	15	0.7397
Total	17.825	17

The p-value is 0.0286.

Since the p-value (0.0286) is less than the significance level (0.05), we can reject the null hypothesis.

Therefore, we can conclude that there is a difference in maze test scores for a strain of laboratory mice trained under different laboratory conditions.