TEST2 stats4.8.21[49]

docx

School

University of Toledo *

*We aren’t endorsed by this school

Course

MISC

Subject

Statistics

Date

Feb 20, 2024

Type

docx

Pages

Uploaded by EarlWaterMouse39

Advanced Statistics Exam 2 Instructor: Robert Topp Group 1: Melissa, Kassandra, DeAirah, Joseph Instructions: Choose the best option for each item. There is one correct answer. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 1. Which of the following is an assumption of Pearson r? A. As one variable increases the other variable increases B. There is a non linear relationship between the variables C. The sample was randomly obtained from the population 2. A positive correlation between two variables means that: A. as scores on one variable increase, scores on the second variable decrease. B. as scores on one variable decrease, scores on a second variable increase. C. one is positive a relationship exists between 2 variables. D. none of the above. 3. You have collected data in the attempt to determine if a relationship exists between anxiety and effective coping behavior. A theory suggests that both low anxiety and high anxiety are associated with decreased effectiveness of coping behavior. Which of the following would be the most helpful in assessing the assumption of linearity aiding your decision as to which measure of association would be appropriate? A. Calculating standard deviations of both variables. B. Inspecting the variability of points along a line of best fit. C. Determine the range of both variables. D. Constructing a scatterplot of the variables. 4. When the variance of a set of data increases, the value of R 2 ? A. increases. B. decreases. C. remains unchanged. 5. Homoscedasticity refers to: A. the similar dispersion of points along a line. B. how well the points along a line are linear. C. variability of the range of points along a line. 6. Which of the following Pearson r correlation coefficients represents the weakest association between variables? A. +.36 B. -.36. C. -.35 D. +.72

7. Pearson r coefficient of -.43 means that approximately: A. 43% of the variance between the two variables is accounted for. B. 57% of the variance between the two variables is accounted for. C. 18% of the variance between the two variables is accounted for. D. -18% of the variance between the two variables is accounted for. E. -43% of the variance between the two variables is accounted for. 8. Which of the following will result in a decreased observed r value? A. Choosing an alpha level of .01 instead of .05. B. Decreased variability for one variable. C. Wider range of scores for one variable. 9. Which of the following would result in an increase in the Pearson r? A. A larger sample size. B. Fewer extreme scores. C. Few outliers. D. A change in the alpha level form .05 to .10. 10. You wish to determine the strength of relationship between gender and if they participated in intermural sports among a population of freshman high school students. Which of the following would be most appropriate if participation is defined as “participation,” or “no participation.” A. Chi Square test of Association/Independence B. Chi Square test for Homogeneity C. Pearson r D. Simple linear regression E. Spearman rho Questions 11-13 are based on the following situation. You are planning to conduct a research study in an attempt to determine whether there is a relationship between subjects’ attitudes toward geriatric patients and the amount of time subjects spent in geriatric patients’ rooms providing care. Attitudes are measured as the sum of 20 questions on a Likert scale with 5 intervals ranging from “strongly agree” to “strongly disagree” and higher scores indicating a more positive attitude toward old people. The sample consists of 35 student nurses, each of whom is providing care to 2 patients for 2 mornings each week for 4 weeks. 11. Which of the following is an appropriate null hypothesis? A. There will be a negative relationship between nurse’s attitudes toward geriatric patients and the amount of time spent in the patient’s rooms. B. There will be no positive relationship between nurses’ attitudes toward geriatric patients and the amount of time spent in the patients’ rooms. C. There will be no significant relationship between nurses’ attitudes toward geriatric patients and the amount of time spent in the patients’ rooms. 12. Which of the following statistical techniques would be most appropriate to test the null hypothesis? A. Chi square test of Independence B. Contingency coefficient C. Pearson r D. Point-Biserial

13. The standard error is an A. estimate of population means which make up the sampling distribution. B. indication of variability the distribution of sample means C. indication of variability of sample raw data which make up the sampling distribution. 14. If you were considering an ANOVA, you could get some idea of whether the assumption of homogeneity of variance has been met by first computing for each group the: A. standard deviation. B. standard error. C. mean score. 15. ANOVA is often more useful than a t -test because A. ANOVA allows for testing of cause-effect questions. B. ANOVA is not limited to small samples C. ANOVA can be used to compare 2 or more groups simultaneously. 16. The assumption of independent groups in a 1-way ANOVA means that: A. subjects are randomly selected. B. subjects can be matched or paired. C. no interaction is expected between subjects. 17. The primary difference between a 1-way ANOVA and a 2-way or multiple-factor ANOVA is the A. between group variance. B. possible interaction effect. C. within group variance. Refer to the following situation for questions 18-21. You have conducted a study to investigate possible differences in urinary output when compared by different body positions. Non-ambulatory patients comprised the target population. The sample was comprised of 60 individuals. None were catheterized. Twenty subjects voided into a bed pan while in a low Fowler’s position. Another twenty voided while in a semi-Fowler’s position. An additional twenty voided while in a high Fowler’s position. Urine was measured in cc’s. All measurements were obtained between 0800 and 0830. 18. Which of the following is the appropriate null hypothesis? A. There will be no significant difference in urinary output among non-ambulatory, non-catheterized patients when compared by body position. B. There will be no significant relationship between urinary output and body position in a population of non- ambulatory, non-catheterized patients. C. Urinary output of non-ambulatory, non-catheterized patients in high Fowler’s position will be equal to or less than that of similar patients in either semi-Fowler’s or low Fowler’s position. 19. Which of the following is the independent variable? A. Body position. B. Time of day. C. Urinary output.

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

20. Which statistical analysis would be most appropriate? A. ANOVA B. ANOVA with Repeated Measures C. Chi Square test for homogeneity D. corr-t E. t-test 21. The observed statistic was 2.83. The critical value is 2.82. What is the appropriate decision regarding the null hypothesis? A. Do not reject the null hypothesis B. Reject the null hypothesis. C. Post hoc analysis is needed to make the appropriate decision. For Items 22 - 28 Please refer to the following example and the excel data set “Spit for Exam 2”. You are interested in Xerostomia or dry mouth syndrome and the impact of this condition on oral bacteria density. You measured saliva production in daily/mls and bacteria (10 6 ) per ml of saliva among 30 patients. 22. What is you research hypothesis? There will be a relationship between saliva production and oral bacterial density. 23. What is your statistical hypothesis set (SHS)? Ho: r = 0 Ho: There will be no relationship between saliva production and oral bacterial density. Ha: r ¹ 0 Ha: There will be a relationship between saliva production and oral bacterial density. 24. What statistical test did you select to address the SHS? Pearson’s r is the appropriate statistical test. We are trying to determine if there is a relationship between two ratio level data. The following assumptions are met: 1. Assumes a linear relationship between the two variables.

2. Homoscedasticity is not violated. 3. Variables are normally distributed.

4. Variables are ratio level data. 5. Sample was randomly obtained from the population. 25. Based upon your analysis what is your decision about the Ho? Decision: reject Ho Inference: There is a significant relationship between saliva production and oral bacterial density. 26. Can your analysis provide a description of shared variance between saliva and bacteria? R 2 = 0.602 The shared variance between saliva and bacteria is 60%. 27. If a patient presented with Xerostomia at your clinic and a saliva production of 850mls/day based upon your analysis above what would you estimate their oral bacterial count to be? Predicted oral bacterial count would be 94.245. Based on regression line: y = 25.395+.081x 28. Based upon your analysis would you recommend treating Xerostomia in order to decrease oral bacteria? [Need to include some statistical support in the answer] No, we would not recommend treating Xerostomia (dry mouth). This is because there is a moderate to strong positive correlation between the variables as evidenced by the R score of .776. This means as saliva amount increases so does bacteria count.

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

For items 29 – 40 refer to the following example. People who receive chemotherapy have stated that an unpleasant metallic taste is present during the drug delivery phase and results in nausea. You have conducted a study to determine if perception of severity of nausea among people receiving chemotherapy differs by whether they have received an intervention to alter the unpleasant taste. Forty people were given hard candies of their choice of flavor. They were instructed to suck on the candy throughout the drug delivery phase or as long as tolerated. Another 40 comprised the control group and received no intervention. Another 40 were given 30 cc of Maalox during the drug delivery phase. Severity of nausea was measured during the drug delivery phase with a 100 mm Visual Analogue Scale with the following means recorded for each group: Control, n=40 [no cost] Group mean = 87.11 Maalox, n=40 [cost $4.35/dose] Group mean = 48.56 Candy, n=40 [cost $.05/dose] Group mean = 66.12 N = 120 29. State the Research Hypothesis: There will be a difference in perceived severity of nausea between at least two of the 3 interventions. 30. State the statistical hypothesis set: Ho: m control = m maalox = m candy Ha: m control ¹ m maalox or m control ¹ m candy or m maalox ¹ m candy Adopt all of the assumptions of the parametric test as being met and complete the table below: 31. Calculate the degrees of freedom for Total Total df = 119 32. Calculate the SS for Within SS (Within) = 213376.02 33. Calculate the MS for Within MS (Within) = 1823.73 34. Calculate the F observed F (obs) = 4.23 ANOVA SUMMARY TABLE Source of Variation df SS MS F Between 2 15445.02 7722.51 4.23 15 Within 117 213376.02 1823.73 Total 119 228821.04 1922.87 228821.04

35. What is the F critical? F (crit) = 3.1504 36. What is your decision regarding the null hypothesis? F (obs) > F (crit) 4.23 > 3.15 Decision: Reject null hypothesis 37. Calculate the post hoc LSD LSD = t .05 (df 117) Ö MSE( 1/n 1 + 1/n 2) = 2.09 Ö 1823.73 (1/40 +1/40) = 2.09(9.5) = 19.855 38. Using the Fisher’s LSD value you calculated in item 61 conduct post hoc comparisons between all of the group means Maalox Candy Control Mean = 48.56 Mean = 66.12 Mean = 87.11 | | | | | | 39. Arrive at an inference based upon your post hoc analysis Inference: The AVOVA model indicated that there is a difference in perceived severity of nausea between the three intervention groups that were studied. LSD post hoc comparisons indicated that the control group had a significantly higher nausea severity that the Maalox or candy groups. Maalox group and Candy group exhibited similar levels of nausea severity. 40. In 2-3 sentences, employing this empirical evidence from above what are your recommendations (if any) to change clinical management of nausea among people receiving chemotherapy According to the post hoc comparisons, chemotherapy patients who were given Maalox and hard candies expressed lower levels of nausea than the control group. Changes to the clinical management of nausea among chemotherapy patients may include the addition of hard candies and Maalox given during the drug delivery phase of treatment. Similar results were seen between the Maalox and candy groups, so offering hard candies may be more cost effective than Maalox.

Spit for Exam 2 subid Salivamlday BacteriaCountx106 1.00 456.00 74.00 2.00 499.00 62.00 3.00 513.00 45.00 4.00 546.00 80.00 5.00 589.00 62.00 6.00 656.00 77.00 7.00 688.00 60.00 8.00 702.00 89.00 9.00 733.00 81.00 10.00 759.00 78.00 11.00 767.00 110.00 12.00 792.00 67.00 13.00 834.00 110.00 14.00 836.00 99.00 15.00 868.00 101.00 16.00 899.00 133.00 17.00 945.00 78.00 18.00 923.00 110.00 19.00 994.00 145.00 20.00 1017.00 82.00 21.00 1052.00 90.00 22.00 1089.00 133.00 23.00 1135.00 89.00 24.00 1178.00 143.00 25.00 1211.00 123.00 26.00 1267.00 138.00 27.00 1309.00 124.00 28.00 1325.00 140.00 29.00 1356.00 127.00 30.00 1388.00 122.00

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

TEST2 stats4.8.21[49]

Related Documents