Question

Researchers believe that the action theory has implication merits in terms of improving academic achievements. An intervention has been designed based on the action theory and implemented on 8 students in an attempt to enhance their grade in Experimental Psychology class. Before the intervention, the experimenter used a set of 20 questions randomly selected from GRE Psychology Subjective question bank to assess students’ understanding of fundamental concepts in psychology. The grade is based on a 0-20 scale, a higher number indicating a higher grade and better academic achievement. After 6-week intervention, the experimenter tested the same group of students with the same 20 questions to assess the grade change (if any). (12 pts) The grades are below:

Subjects	Pre-intervention	Post-intervention
1	5	6
2	7	7
3	9	12
4	5	5
5	9	10
6	7	8
7	8	13
8	4	5

Be sure to include the following parts: a) State the null and alternative hypothesis. (1 pts) b) Report df and critical values. (1 pts) c) Calculate the value of your test statistic from the data. (6 pts) d) Evaluate your hypotheses and make statistical decision. (2 pts) e) Interpret the results and answer the research question - Does this intervention improve students’ grade in Experimental Psychology class? (2 pts)

Answer 1

A. Null hypothesis: Action theory has no significant impact on academic achievements.
Alternative hypothesis: Action theory significantly improves academic achievements.
B. The df is 7. The critical value at the 0.05 level is 2.365.
C. The value of t is 2.50998.
D. Based on these results, the null hypothesis should be rejected.

Please post the other questions separately as we are supposed to answer just one question or four sub parts of the same question.