Statistics discussion
SPSS Cumulative Assignment Instructions
The following research questions can be answered using one of the five tests you have learned so far: singlesample ttest, pairedsamples ttest, independentsamples ttest, oneway ANOVA, or twoway ANOVA. Use the information in the tables to construct your SPSS data file, just as you have been doing in “Part Two” of each homework assignment. There is only one correct choice of analysis for each question. The assessment is openbook and note.
For each problem involving a test of significance, your answer should include: A) the output and an appropriate graph from SPSS; B) a statistical statement (i.e. t(19) = 1.79, p = .049); and C) a sentence summarizing the results (i.e. “There was a significant difference between the two groups on the variable…” or “There was no significant difference….” etc.).
For ANOVA problems: Report statistical findings and make statements for all main effects and interaction effects. Use the Fisher LSD test for any analyses requiring post hoc tests.
1. An entrepreneur claims that he has developed a program that can increase the IQ of adolescent students. To test this claim a psychologist administers the WISC (an IQ score for children) to a group of students before and after completing the training program. Analyze the data to test the entrepreneur’s claim. (16 pts)
Student 
IQ before 
IQ after 
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 
103 85 94 106 74 98 83 93 103 96 109 115 86 122 112 126 118 72 
99 89 90 108 74 99 80 99 107 93 111 117 83 122 120 131 116 74 
2. The staff at a local psychiatric facility wants to determine whether implementing a nosmoking rule significantly decreases the length of stay of inpatients. In order to test this claim, they compared the length of stay of patients admitted before a No Smoking rule was implemented to another group of patients admitted after the No Smoking rule. Evaluate the claim that the average length of stay was significantly shorter for the group admitted after the facility implemented the rule. (16 pts)
Smoking Allowed 
No Smoking 

8 5 2 5 8 6 4 14 
7 15 12 8 4 13 10 8 
5 10 7 8 2 3 2 4 
4 8 4 5 2 4 6 7 
3. Depressed patients are randomly assigned to one of 3 therapists. At the end of 3 months, each patient completes a standardized test of depression (higher scores indicate higher level of depression). The patients’ scores are shown below. Analyze the data to determine how effective these 3 therapists are at treating depression (assume that before the treatment, all 3 groups of patients had the same average depression score). (16 pts)
Therapist 1 
Therapist 2 
Therapist 3 
35 37 35 37 36 33 39 
36 37 37 31 39 35 32 
29 32 25 28 33 30 32 
4. In light of all the weight loss misinformation and fad diets, a medical researcher determines to evaluate several of them. She randomly assigns volunteers (identified as clinically obese) to one of 4 diets. She is a firm believer in the benefits of exercise so she also assigns them to either the exercise or no exercise group. After 3 months, she compares the pounds lost for each condition. Was there a significant effect of the diets and exercise on weight loss? (16 pts)
Exercise 
Low Carb 
South Beach 
Adkins 
Weight Watchers 
26 28 30 25 20 
28 22 18 
25 21 24 29 
28 28 30 25 26 

No Exercise 
15 20 18 
18 12 15 15 
17 19 28 25 21 
34 25 30 28 
5. Infants exposed to cocaine in their mother’s womb are thought to be at high risk for major birth defects. Thirteen infants born to mothers who are addicted to cocaine are administered the Brazelton Neonatal Assessment one day after birth. For these babies, their scores were as follows
Brazelton Scores 
6.25 4.50 8.50 5.50 3.00 7.90 7.50 5.30 6.80 7.50 5.25 7.45 6.80 
For the general population, babies normally score an 8.5. Is this group of babies significantly lower than normal? (16 pts.)
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