Question

Dr. Abba believes A developmental psychologist believes that word chunking impairs vocabulary development. that students will rate their life satisfaction lower at the completion of a anthropology course. To test this hypothesis, he collects life satisfaction ratings for all students in the course at the start of the semester and again at the end of the semester. Below are the data. What can be concluded with an an α of 0.01?

start	end
91 84 86 66 90 88 87 79 88 87	82 75 82 81 91 81 87 76 81 82

c) Obtain/compute the appropriate values to make a decision about H₀.
(Hint: Make sure to write down the null and alternative hypotheses to help solve the problem.)
critical value =  ; test statistic =
Decision:  ---Select--- Reject H0 Fail to reject H0

d) If appropriate, compute the CI. If not appropriate, input "na" for both spaces below.
[  ,  ]

e) 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

f) Make an interpretation based on the results.

Student life satisfaction is significantly lower at the completion of the anthropology course.

Student life satisfaction is significantly higher at the completion of the anthropology course.    

Student life satisfaction is not significantly impacted by the anthropology course.

Answer 1

c)

Answer:

critical value = 2.821

test statistic = 1.242

Decision: Fail to reject H0

Explanation:

Since we are doing repeated measures on the same subject, this is a paired sample study design.

Hypothesis

The null hypothesis and the alternative hypothesis are defined as,

This is a right-tailed test.

Critical value

The significance level of the test is 0.01

The t critical value is obtained from the t critical value table for significance level = 0.01, the degree of freedom =n-1 = 9, and for a one-tailed test.

Test statistic

The t statistic for the paired-sample t-test is obtained using the following formula,

From the data values,

.	Start	End	Difference = Start - End
.	91	82	9
.	84	75	9
.	86	82	4
.	66	81	-15
.	90	91	-1
.	88	81	7
.	87	87	0
.	79	76	3
.	88	81	7
.	87	82	5
Average	.	.	2.8
St. Dev.	.	.	7.131
n	.	.	10

Decision:

Since the t statistic = 1.242 is less than the t critical value, the null hypothesis is not rejected at a 1% significance level.

d)

Answer:

Explanation:

The 99% confidence interval for the mean difference is obtained using the following formula,

where the t critical value is obtained from the t critical value table for significance level = 0.01, the degree of freedom =n-1 = 9, and for a two-tailed test.

From the data values,

e)

Answer:

d = 0.397, medium effect

r^2 = 0.146, medium effect

Explanation:

Cohen's d

The effect size d is obtained using the following formula,

The value of d = 0.4 corresponds to medium effect

r squared

The effect size r squared is obtained using the following formula,

The value of r squared = 0.15 corresponds to medium effect

f)

Answer:

Student life satisfaction is not significantly impacted by the anthropology course.

Explanation:

From the hypothesis test in part c, the null hypothesis is failed to rejected which means the mean difference is not less than zero. Hence we can conclude that there is not sufficient evidence to conclude that student life satisfaction is lower at the completion of an anthropology course