HW #4

pdf

School

California State University, Sacramento *

*We aren’t endorsed by this school

Course

110

Subject

Statistics

Date

Feb 20, 2024

Type

pdf

Pages

Uploaded by JusticeMetal15721

Homework #4. Examining the Relationship: Chi-square test, correlation, & regression Part I.Reading Journal Articles: Chi-square test (10 points) The sampling frame included the following: only heads of households, persons 16 years of age and older who self-identified as Hispanic regardless of race, householders who worked at some point [during the year], and householders who were employed in their own unincorporated business and professional practice … The final sample consisted of 7,760 Hispanic self-employed persons, 64% (n = 4,931) who were self-employed men and 36% (n = 2,829) who were self-employed women. 1. What is the value of chi-square (χ2) for the occupation of “Service”? (1 point) The chi-square value is 87.99 2. What is the p -value for the difference between the percentage of self-employed men who has “Bachelor’s degree or more” and the percentage of self-employed women who has “Bachelor’s degree or more”? (1 point) P = 11 - 4.7 = 6.3% 3. Based on Table 1 above, should the difference between the percentage of self-employed men and self-employed women who are “Managerial and professional” be declared to be statistically significant, and if so, at which level? Explain your answer using the p -value. (2 points) Yes it is statistically significant because 0.063 is greater than 0.05 4. Compare the probability level for “High school graduate” with the probability level for “Some college.” Which one is more statistically significant? Explain your answer. (2 points) High school graduate is statistically more significant because 20.5-18.9= 1.6% 0.016 Some college 22.1-22.5=-0.4 , 0.4% 5. Based on Table 1, should the null hypothesis for the difference in the percentages of men and women for education with “Less than high school” be rejected? (yes/no) Explain your answer. (2 points) The NH is rejected because it’s a greater value 6. Which statement below is correct? (2 points) A. Based on Table 1, we conclude that there is no gender difference in “Technical, sales, or administrative” jobs among self-employed Hispanic sample. B. Table 1 reports that statistically significantly higher number of self-employed men are working in “Technical, sales, or administrative” jobs, while statistically significantly larger number of self-employed women are doing “Craft, precision production, and repair” work.

C. There is a statistically significant difference in education level, that more self-employed women are high school graduates than self-employed men. D. Table 1 tests eight null hypotheses total. Part II. Reading Journal Articles: Correlation (6 points) Participants were recruited from an elementary school located in an urban section of Los Angeles County… The families living in the surrounding neighborhoods have been conceptualized as "working poor" in recent demographic studies of the Los Angeles region… All children in 16 third-, fourth-, and fifth-grade classrooms from the participating school were invited to take part in the project. Of these children, 80% returned positive parental permission and assented to participate. Children completed the Community Experiences Questionnaire… Items on this measure range in severity from threats to shootings; the 4-point scale ranges from 1 ( never ) to 4 ( a lot of times ). [An inventory] contained four items assessing bullying by peers ("kids who get hit or pushed by other kids," "kids who get bullied or picked on by other kids," "kids who have mean things said about them by other kids," and "kids who get left out of fun games or play when other kids are trying to hurt their feelings")… Note . Column heading of “1” refers to “1. Community violence exposure” in the rows; column heading of “2” refers to “2. Bullying by peers” in the rows; and so on. 1. What is the value of the correlation coefficient for the relationship between “Community violence exposure” and “SAT-9 Reading”? (1 point) 2. What is the value of the correlation coefficient for the weakest relationship in the table? (1 point) -0.07 3. Which of the following statements is incorrect? (2 points) A. There are four positive correlations reported in the Table. B. The correlation between “Community violence exposure” and “GPA” is weaker than the correlation between “Community violence exposure” and “Bullying by peers.”

C. There is a moderate strength of correlation between “SAT-9 Mathematics” and “GPA.” D. According to the Table, the higher the children have been exposed to community violence, the more likely they also have been bullied by peers. 4. Which one of the following pairs of variables has a stronger relationship between them? (1 point) SAT-9 mathematics A. "Community violence exposure" and "Bullying by peers" B. "Bullying by peers" and "GPA" 5. How many relationships are to be considered as moderate size of correlation from the Table? (1 point) 4 Part III. Reading Journal Articles: Regression (6 points) In the study described below, the subjects' body fat was pre-tested and post-tested to assess the effects of a very-low-calorie diet. Hydrodensitometry measures body fat in water; bioelectrical impedance analysis (BIA) is an electrical measure of body fat. Seventeen subjects (nine women and eight men) from an outpatient, hospital-based treatment program for obesity volunteered. Within 10 days after the baseline measures (i.e., pretest measures) were obtained, the subjects began the 12-week VLCD [very low calorie diet] portion of the...program .... At the end of the 12 weeks, all measurements were repeated in the laboratory. Correlation between hydrostatic weighing and bioelectrical impedance was r = 0.63 for the 16 pretests and r = 0.84 for the 17 posttests. (Hydrostatic measurement of one male subject was not possible on the pretest because of discomfort in the water.) Correlation for the combined pretest and posttest trials ( n = 33) was r = .837. 1. From Figure 2 above, identify the coefficient of X ( b ) and the intercept ( a ). (1 point) 0.77 and 5.44 2. If the line in Figure 2 was extended to the left, at what value would it meet the vertical axis (i.e., y-axis)? (Give an answer that is precise to one decimal place.) (1 point) Y = 5.44

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

3. Use the equation for the straight line shown in Figure 2 to predict the percentage of body fat as measured by BIA for a person who has 50% body fat as measured by hydrodensitometry. Make sure the unit of the body fat is “%.” (1 point) 43.94% 4. Use the equation for the straight line shown in Figure 2 to predict the percentage of body fat as measured by BIA for a person who has 20% body fat as measured by hydrodensitometry. Make sure the unit of the body fat is “%.” (1 point) 20.84% 5. Compare your answers to questions #3 and #4. Do your answers make sense considering the coefficient of X ( b )? Explain your answer. (2 points) Yes the answers make sense, due to the body fat increase from #4 to #3 Part IV.SPSS Exercise (55 points) Tasks SPSS Commands Open SPSS data file File à Open à Data… Chi-square test Analyze à Descriptive Statistics à Crosstabs… Correlation Analyze à Correlate à Bivariate… Regression Analyze à Regression à Linear… Research question #1. Is there an association between the juveniles’ gender (male or female) and whether or not the juveniles earned off-campus privilege after treatment (i.e. post-treatment) (yes/no)?(18 points) yes SPSS Dataset SPSS Data for HW (500 cases).sav (available in Canvas) Variable Names in the dataset gender : Juveniles’ gender (male or female) campus2 : Whether or not juveniles earned off-campus privilege in post -treatment 1. Identify the dependent variable (DV) and its level of measurement. (2 points) The DV is gender and where or not they earned off campus privilege

2. Identify the independent variable (IV) and its level of measurement. (2 points) The IV is earned off campus privileges 3. State 1) the research hypothesis (non-directional), and 2) the null hypothesis. Make sure you include both DV and IV in the hypotheses. (2 points) The RH is who from Male or Female earn off campus privileges NH is Gender (female and male) 4. Based on the research question, what type of statistical analysis should be used? Explain your answer. (2 point) descriptive analysis 5. Run the statistical analysis using the SPSS. The SPSS outputs should be exported into the PDF file, and submitted separately. (1 point for correct SPSS output submission) 6. Based on the results in #5 above, answer the following questions. For “statistical significance,” the rejection level is set to p =0.05. (total 9 points) a. From the SPSS tables in #5 above, find and report the observed frequency of the male juveniles who earned off-campus privileges post-treatment. (1 point) . 501 b. From the SPSS tables in #5 above, find and report the expected frequency of the female juveniles who did not earn off-campus privileges post-treatment. (1 point) .330 c. From the SPSS tables in #5 above, the observed frequencies are shown as whole numbers (no decimals) and the expected frequencies are reported as the decimal numbers. Explain the reason. (1 point) The decimals are acceptable due to the expected value d. From the SPSS tables in #5 above, find and report the statistics of 1) chi-square ( χ 2 ), and 2) p -value. (2 point) N/A e. Based on the SPSS tables in #5 above, can you reject or fail to reject the null hypothesis? Explain your answer. (2 points) We would reject the null hypothesis due to the inaccurate reading f. Based on the SPSS tables in #5 above, what is your conclusion about the association between gender and the off-campus privilege in post-treatment? Explain your answer. (2 points) My conclusion is that male and female off campus privileges is equal

Research question #2. Is there a relationship between the relationship between the quality of therapist-client relationship and the change of the scores from pretest to posttest (the larger the change, the better the outcome)? (19 points) SPSS Dataset SPSS Data for HW (500 cases).sav (available in Canvas) Variable Names in the dataset qual : Quality of therapist-client relationship change : Change of the scores from pretest to posttest 1. Based on the research question alone, it is not possible to determine what the dependent variable (DV) or the independent variable (IV) are. Explain the reason. (1 point) It is NOT possible to determine the DV & IV in this situation, only the therapist, client relationship is mentioned 2. Identify the first variable (Var 1) and its level of measurement. (2 points) Therapist 3. Identify the second variable (Var 2) and its level of measurement. (2 points) Client 4. State 1) the research hypothesis (non-directional), and 2) the null hypothesis. Make sure you include both DV and IV in the hypotheses. (2 points) RH: relationships between clients and therapists 5. Based on the research question, what type of statistical analysis should be used? Explain your answer. (2 point) Inferential statistics 6. Run the statistical analysis using the SPSS. The SPSS outputs should be exported into the PDF file, and submitted separately. (1 point for correct SPSS output submission) 7. Based on the results in #6 above, answer the following questions. For “statistical significance,” the rejection level is set to p =0.05. (total 9 points) a. From the scatterplot in #6 above, explain whether the type of correlation between the quality of therapist-client relationship and the change of the score from pretest to posttestis positive or negative, and its meaning. (2 point) b. From the SPSS tables in #6 above, find and report the statistics of 1) Pearson’s correlation,and 2) p -value. (2 points)

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

c. Based on the SPSS tables in #6 above, can you reject or fail to reject the null hypothesis? Explain your answer. (2 points) d. Based on the SPSS tables in #6 above, what is your conclusion about the relationship between quality of therapist-client relationship and the change of the scores from pretest to posttest? Explain your answer, including 1) type of correlation and its meaning, 2) statistical significance, and 3) strength/magnitude of correlation. (3 points) Research question #3. Does the number of canceled therapy sessions affect the change of the scores from pre-test to post-test among juveniles? (18 points) SPSS Dataset SPSS Data for HW (500 cases).sav (available in Canvas) Variable Names in the dataset change : Change of the scores from pretest to posttest (measured by points) cancel : Number of canceled therapy sessions (measured by sessions) 1. Identify the dependent variable (DV) and its level of measurement. (2 points) The IV: does the number of canceled therapy sessions affect the change of the scores 2. Identify the independent variable (IV) and its level of measurement. (2 points) The DV: from the pre-test to the post-test among juveniles 3. State 1) the research hypothesis (non-directional), and 2) the null hypothesis. Make sure you include both DV and IV in the hypotheses. (2 points) The RH: canceled therapy affecting scores of juveniles & NH: or will it stay the same? Or be the same compared to non-canceled therapy sessions. 4. Based on the research question, what type of statistical analysis should be used? Explain your answer. (2 point) Independent T test as it is measuring two groups 5. Run the statistical analysis using the SPSS. The SPSS outputs should be exported into the PDF file, and submitted separately. (1 point for correct SPSS output submission) 6. Based on the results in #5 above, answer the following questions. For “statistical significance,” the rejection level is set to p =0.05. (9 points total)

a. From the SPSS tables in #5 above, find and report the statistics for 1) the coefficient of X ( b ), 2) p -value of the coefficient of X , and 3) the intercept ( a ) (3 points) b. Provide the interpretation of the coefficient of X ( b ), identified in your 5-a) above. Your interpretations should include two variables, “change of the scores” and “number of canceled therapy sessions.” (1 point) c. Provide the interpretation of the intercept ( a ), identified in your 5-a) above. Your interpretations should include two variables, “change of the scores” and “number of canceled therapy sessions.” (1 point) d. Based on the SPSS tables in #5 above, can we reject or fail to reject the null hypothesis? Explain your answer. (2 point) e. Based on the SPSS tables in #5 above, write the regression equation. (1 points) f. Using the regression equation in 5-e) above, predict the change of the scores from pretest to posttest for a juvenile who has canceled 3 sessions. (1 point) California State University, Sacramento Page 1

HW #4

Related Documents