Question

1. A biopsychologist is interested in studying the effects of marijuana on cognitive skills by studying a group of 7 rats. He puts each rat in a maze and measures the time it takes the rat (in minutes) to find the cheese at the end of the maze. He then puts a mask on the rat and has it inhale marijuana smoke for 5 seconds. He then puts the rat back in the maze, and records its time to reach the cheese. Twenty minutes later he puts the rat back in the maze to test for lasting effects of the drug. The tables below summarize the data and part of the data analysis:

Source SS df MS F p eta2

IV    33.24 2 ___ ____ ___ ____

Error 43.43 12 ___

Subjects 27.13 6

Total ____ 20  

a. Describe the statistical test to be done.

b. State the null and alternative hypotheses.

c. What is the critical value of the test statistic? What is the decision rule for rejecting the null hypothesis?

CV:         _________________________          df:___________             Reject H₀ if F ________________

Based on the findings presented in your summary table, did you reject H_o? (Circle or highlight response)

Reject H_o                                                                             Fail to reject H_o

Answer 1

Source	SS	df	MS	F	p	eta2
IV	33.24	2	16.62	4.592	.033077	32.02%
Error	43.43	12	3.619
Subjects	27.13	6
Total	103.8	20

a)The statistical test to be done is ANOVA. Above is the table in which i have specified all the missing values.

b) The null and alternative hypothesis is as follows:

Ho:The time required for rats to reach at cheese is same before and after marijuana that is marijuana has no significant impact on rats

H1:The time required for rats to reach at cheese is different before and after marijuana that is marijuana has significant impact on rats.

c)

CV=4.592

df=(2,12)

table value of F is =3.885

Reject Ho if F>3.885 (at 5%)

d)

Reject Ho.

As the critical value is greater than observed value reject Ho.