Introduction to Statistics Part A - Outputs 1. A sa.docx
- 1. Introduction to Statistics Part A - Outputs: 1. A sample of university employees had been assembled. An output concerning their education is presented below. Study the output and answer the following questions: a. What is the mean, median and the standard deviation? b. Firstly, what is the interquartile range, and secondly, how many education years has the most educated employee? c. what is the number of education years that 36% of the sample has that number of education years or below it? Answer the same question for 83%. d. Firstly, how many employees has 12 education years or less? Secondly, how many employees have missing values in the variable education years? Statistics
- 2. Highest Year of School Completed 1510 7 12.88 12.00 12 2.984 8.904 20 0 20 19455 9.00 12.00 12.00 12.00 15.00 16.00
- 3. Valid Missing N Mean Median Mode St d. Dev iation Variance Range Minimum Maxim um Sum 10 25 36 50 75 83
- 4. Percentiles 2. Researcher which studies the field of eating disorders checked the correlation between subjects body image ranking and the degree to which they restrict food intake. Study the output and answer the following questions: Highest Year of School Completed 2 .1 .1 .1 5 .3 .3 .5 5 .3 .3 .8 6 .4 .4 1.2 12 .8 .8 2.0 25 1.6 1.7 3.6 68 4.5 4.5 8.1
- 5. 56 3.7 3.7 11.9 73 4.8 4.8 16.7 85 5.6 5.6 22.3 461 30.4 30.5 52.8 130 8.6 8.6 61.5 175 11.5 11.6 73.0 73 4.8 4.8 77.9 194 12.8 12.8 90.7 43 2.8 2.8 93.6 45 3.0 3.0 96.6 22 1.5 1.5 98.0 30 2.0 2.0 100.0 1510 99.5 100.0 7 .5 1517 100.0 0 3 4
- 7. NAMissing Total Frequency Percent Valid Percent Cumulat iv e Percent Correlati ons 1 .383** .000 217 217 .383** 1 .000 217 217 Pearson Correlation Sig. (2-tailed) N Pearson Correlation Sig. (2-tailed) N
- 8. Body perception Restriction of f ood intake (f asting) Body perception Restriction of f ood intake (f asting) Correlation is signif icant at the 0.01 lev el (2-t ailed).**. 1. What can be inferred from the table? a. There is a significant negative correlation between the variables. b. There is a moderately negative correlation between the variables. c. There is a moderately positive correlation between the variables. d. There is a weak positive correlation between the variables. 2. Report the correlation. 3. The following output present a regression done in order to
- 9. predict the number of SMS messages a person sends to hishers partner by the length of the relationship (in years). Study the output and answer the following questions: Regression Model Summary Model R R Square Adjusted R Square Std. Error of the Estimate 1 -.661(a) .436 .435 123.540 a Predictors: (Constant), Duration of relationship (years) ANOVA(b) Model Sum of Squares df Mean Square F Sig. 1 Regression 6010.000 1 100.000 365.381 .000(a)
- 10. Residual 7776.340 472 160.840 Total 13776.340 473 a Predictors: (Constant), Duration of relationship (years) b Dependent Variable: SMS Coefficients(a) Model Unstandardized Coefficients Standardized Coefficients t Sig. B Std. Error Beta B Std. Error 1 (Constant) 15.178 2821.912 -6.496 .000 Duration of relationship (years) -0.183 204.547 .661 19.115 .000 a Dependent Variable: SMS
- 11. 1. What is the percentage of explained variance? 2. Write the regression line equation. 3. Brad and Angelina are married for 25 years. According to this analysis, how many SMS messages should Brad send Angelina? 4. A researcher is conducting a research on the effects of sociability on mood. He is using a questionnaire in order to assess sociability. Study the output concerning the reliability check and answer the following questions: Reliability Scale: sociability Case Processing Summary N % Cases Valid 198 99.0
- 12. Excludeda 2 1.0 Total 200 100.0 a. Listwise deletion based on all variables in the procedure. Reliability Statistics Cronbach's Alpha Cronbach's Alpha Based on Standardized Items N of Items .627 .659 8 Inter-Item Correlation Matrix 1 2 3 4 5 6 7 8 1. I like to see friends 1.000 .605 -.024 .189 .501 -.435 .451 .396 2. I talk a lot with friends on the phone .605 1.000 -.001 .362
- 13. .492 -.837 .509 .424 3. I like chocolate -.024 -.001 1.000 .003 .009 .001 -.001 -.017 4. I go to a lot of parties .189 .362 .003 1.000 .408 -.557 .430 .411 5. I have many friends .501 .492 .009 .408 1.000 -.243 .675 .510 6. I like to read alone at home -.435 -.837 .001 -.557 -.243 1.000 -.408 -.650 7. Romantic relationship are important .451 .509 -.001 .430 .675 -.408 1.000 .495 8. I feel good with my social status .396 .424 -.017 .411 .510 - .650 .495 1.000 Item-Total Statistics Scale Mean if Item Deleted Scale Variance if Item Deleted Corrected Item-
- 14. Total Correlation Squared Multiple Correlation Cronbach's Alpha if Item Deleted 1. I like to see friends 17.4495 26.188 .515 .443 .561 2. I talk a lot with friends on the phone 17.2374 24.009 .555 .472 .534 3. I like chocolate 16.1919 29.811 .007 .018 .686 4. I go to a lot of parties 15.9697 23.826 .399 .330 .571 5. I have many friends 16.7273 21.753 .666 .546 .489 6. I like to read alone at home 14.6768 35.540 -.320 .196 .753 7. Romantic relationship are important 17.0556 23.220 .634 .528 .512 8. I feel good with my social status 16.4192 23.260 .473 .397 .547
- 15. 1. What is the number of subjects who's answers had been entered to the reliability check? 2. What is the internal reliability of the sociability questionnaire? 3. which item (or items) would you suggest to change or omit (leave out)? explain why, both from a statistical point of view and from the theoretical point of view. Part B - statistical comprehension: 1. Study the table and answer the following questions: Taken from Somer, E., Maguen, S., Or-Chen, K. & Litz, B. (2008). Managing Terror: Differences between Jews and Arabs in Israel. International Journal of Psychology, 42, 1-9. Table 1 Demographic Variables of Jewish-Israelis and Arab-Israelis
- 16. Demographic Characteristics Jewish- Israelis (n = 100) Arab- Israelis (n = 100) Statistic comparing the two groups Age (years) M = 43.60 (SD = 16.76) M = 36.62 (SD=13.02) t(198) = 10.82**
- 19. Table 1 Demographic Variables of Jewish-Israelis and Arab-Israelis Demographic Characteristics Jewish- Israelis (n = 100) Arab- Israelis (n = 100) Statistic comparing the two groups Religiosity Religious laroitidarT raluTra %10
- 21. *p<0.05 **p<0.01 1. What is the conclusion from the results of the test done between nationality and age ? Did a significant correlation had been found? Which test did the researchers use? 2. The Pearson correlation between all the of the research variables is displayed in the following table. Please report (in length) what is the most important correlation. explain why. Table 2 Correlations Among Variables in Regression Models Variable 1 2 3 4 5 6 7 8 9 10 1. PTSD -- 2. Depression .77** -- 3. Somatization .58** .66** -- 4. Group -.38** -.46 ** -.04 --
- 22. 5. Age .03 -.03 .19** .23** -- 6. Gender .21** .23** .20** .11 .05 -- 7. Education -.22** -.23** -.27** .16* .06 -.05 -- 8. Religiosity -.20** -.21** -.09 .34** .10 -.03 -.26** -- 9. Marriage -.13 -.12 -.09 .14 -.47** -.04 .05 .15* -- 10. Birthplace -.15 -.21** .02 .48** .45** .11 .08 .19** -.07 -- *p<0.05 **p<0.01 Good luck!