In: Statistics and Probability
A team of psychologists hypothesize that feeling sick is associated with liking a flavor. They design a study in which rats are randomly split into two group. In one group the rats are given an injection of lithium chloride immediately following consumption of saccharin-flavored water. Lithium chloride makes rats feel sick. The rats in the other group were not given Lithium chloride after drinking the flavored water. The next day, all rats could drink saccharin-flavored water. The amount of saccharin-flavored water consumed (in milliliters) for all rat for the next day are given below. What can the psychologists conclude with α = 0.01?
lithium | no lithium |
---|---|
4 3 1 3 2 6 8 6 5 |
6 9 6 7 9 7 5 6 7 |
a) What is the appropriate test statistic?
---Select--- na z-test One-Sample t-test Independent-Samples t-test
Related-Samples t-test
b)
Condition 1:
---Select--- lithium chloride saccharin-flavored water disliking a
flavor no lithium chloride the rats
Condition 2:
---Select--- lithium chloride saccharin-flavored water disliking a
flavor no lithium chloride the rats
c) Compute the appropriate test statistic(s) to
make a decision about H0.
(Hint: Make sure to write down the null and alternative hypotheses
to help solve the problem.)
p-value = ; Decision: ---Select---
Reject H0 Fail to reject H0
d) Using the SPSS results,
compute the corresponding effect size(s) and indicate
magnitude(s).
If not appropriate, input and/or select "na" below.
d = ; ---Select--- na trivial
effect small effect medium effect large effect
r2 = ; ---Select--- na
trivial effect small effect medium effect large effect
e) Make an interpretation based on the
results.
Rats that were given lithium chloride drank significantly more saccharin-flavored water than those that were not given lithium chloride.Rats that were given lithium chloride drank significantly less saccharin-flavored water than those that were not given lithium chloride. There is no significant difference in saccharin-flavored water drank between rats that were given lithium chloride and those that were not.
A team of psychologists hypothesize that feeling sick is associated with liking a flavor. They design a study in which rats are randomly split into two group. In one group the rats are given an injection of lithium chloride immediately following consumption of saccharin-flavored water. Lithium chloride makes rats feel sick. The rats in the other group were not given Lithium chloride after drinking the flavored water. The next day, all rats could drink saccharin-flavored water. The amount of saccharin-flavored water consumed (in milliliters) for all rat for the next day are given below. What can the psychologists conclude with α = 0.01?
lithium |
no lithium |
4 |
6 |
a) What is the appropriate test statistic?
---Select--- Independent-Samples t-test
b)
Condition 1:
---Select--- lithium
Condition 2:
---Select--- no lithium
c) Compute the appropriate test statistic(s) to
make a decision about H0.
(Hint: Make sure to write down the null and alternative hypotheses
to help solve the problem.)
test statistic = -3.067
p-value = 0.007 ;
Decision: ---Select--- Reject H0
Group Statistics |
|||||
group |
N |
Mean |
Std. Deviation |
Std. Error Mean |
|
VAR00002 |
lithium |
9 |
4.22 |
2.224 |
.741 |
No lithium |
9 |
6.89 |
1.364 |
.455 |
Independent Samples Test |
||||||||||
Levene's Test for Equality of Variances |
t-test for Equality of Means |
|||||||||
F |
Sig. |
t |
df |
Sig. (2-tailed) |
Mean Difference |
Std. Error Difference |
95% Confidence Interval of the Difference |
|||
Lower |
Upper |
|||||||||
VAR00002 |
Equal variances assumed |
2.813 |
.113 |
-3.067 |
16 |
.007 |
-2.667 |
.870 |
-4.510 |
-.823 |
Equal variances not assumed |
-3.067 |
13.275 |
.009 |
-2.667 |
.870 |
-4.541 |
-.792 |
d) Using the SPSS results,
compute the corresponding effect size(s) and indicate
magnitude(s).
If not appropriate, input and/or select "na" below.
d = ( 6.89-4.22)/sqrt((2.224^2+1.364^2)/2)= 1.447301
d = 1.45 ; ---Select large effect
r2 = ; na
e) Make an interpretation based on the
results.
Rats that were given lithium chloride drank significantly less saccharin-flavored water than those that were not given lithium chloride.