Question

To demonstrate flavor aversion learning (that is, learning to dislike a flavor that is associated with becoming sick), researchers gave one group of laboratory rats an injection of lithium chloride immediately following consumption of saccharin-flavored water. Lithium chloride makes rats feel sick. A second control group was not made sick after drinking the flavored water. The next day, both groups were allowed to drink saccharin-flavored water. The amounts consumed (in milliliters) for both groups during this test are given below.

Amount Consumed by Rats That Were Made Sick (n = 4)	Amount Consumed by Control Rats (n = 4)
4	13
5	7
1	11
3	9

(a) Test whether or not consumption of saccharin-flavored water differed between groups using a 0.05 level of significance. State the value of the test statistic. (Round your answer to three decimal places.)


State the decision to retain or reject the null hypothesis.

-Retain the null hypothesis.

-Reject the null hypothesis.    

(b) Compute effect size using eta-squared (η²). (Round your answer to two decimal places.)
η² =

Answer 1

a)

x1    =	3.250	x2      =	10.000
s1    =	1.708	s2      =	2.582
n1    =	4	n2     =	4
Pooled Variance Sp2=((n1-1)s21+(n2-1)*s22)/(n1+n2-2)=				4.7917

standard error se =Sp*√(1/n1+1/n2)=			1.548
test stat t =(x1-x2-Δo)/Se=		-4.361

Reject the null hypothesis.   

b)

effect size =η2=ω2=t2/(t2+df) =

0.76