HLTH 501 EXCEL EXERCISE WEEK 3 The standard deviation is a measure of how much variation is present in a sample or population. Refer to the Descriptives table in the spreadsheet and identify the standard deviation for the weights of the three groups. Enter the standard deviation next to the variable names below. A. Wt_Grp_1 = _____ B. Wt_Grp_2 = _____ C. Wt_Grp_3 = _____ For the three histograms below enter the letter corresponding to the Wt_Grp with a standard deviation most consistent with the shape of the histogram. Letter ______ (1 pt) Letter: ______ (1 pt) Letter ______ (1 pt) Page 1 of 2 HLTH 501 Refer to the TwoSampleTTest tab in the assignment spreadsheet. Answer the following questions: Which group of subjects is least alike with regard to weight? ____ (1 pt) Do the two groups have significantly different mean weights? (Yes/No)_____ (1 pt) Refer to the PairedTTest tab in the assignment spreadsheet. Answer the following questions: Which group of subjects are least alike with regard to blood pressure? ____ (1 pt) Do the two groups have significantly different mean blood pressures? (Yes/No)______ (1 pt) To answer the question: Is the 2nd diastolic blood pressure significantly different between Groups 1, 2, and 3refer to the ANOVA tab in the assignment spreadsheet. Which group is most alike with respect to blood pressure? ____ (1 pt) Is there a significant difference in mean blood pressure between the groups? ______ (1 pt) Page 2 of 2 HLTH 501 WEEK 3 PROBLEMS30 POINTS 10 points per problem. Put answers in the table: 1. 2. 3. 1. A clinical trial is conducted comparing a new pain medication for arthritis. Participants are randomly assigned to receive the new medication or a placebo. The outcome is pain relief within 30 minutes. The data are shown below. New Medication Placebo Pain Relief 44 21 No Pain Relief 76 99 Estimate the risk difference in pain relief between treatments = Estimate the relative risk in pain relief between treatments = Estimate the odds ratio in pain relief between treatments = The upper and lower limits of the are shown below Lower Limit of CI: ____0.41____ Upper Limit of CI: ___1.61_____ Based on the Confidence Interval values which of the following are true? Page 1 of 3 HLTH 501 A. One can be 95% confident that the true value will be greater than the upper limit. B. One can be 95% confident that the true value will be greater than the lower limit. C. One can be 95% confident that the true value will between the upper and lower limit. D. a and b 2. The following data were collected in a clinical trial evaluating a new compound designed to improve wound healing in trauma patients. The new compound is compared against a placebo. After treatment for 5 days with the new compound or placebo the extent of wound healing is measured and the data are shown below. Treatment New Compound (n=125) Placebo (n=125) 0-25% 15 36 Percent Wound Healing 26-50% 51-75% 37 32 45 34 76-100% 41 10 Is there a difference in the extent of wound healing by treatment? (Hint: Are treatment and the percent wound healing independent?) Run the appropriate test at a 5% level of significance. df= ________ alpha= ________ 2 Reject H0 if > ________ Compute expected frequencies Expected Frequency = (Row Total * Column Total)/N. Complete the expected frequencies for each cell. Treatment New Compound Placebo Total Compute 0-25% 15 ( ) 36 ( ) 51 Percent Wound Healing 26-50% 51-75% 37 32 ( ) ( ) 45 34 ( ) ( ) 82 66 Total 76-100% 41 ( ) 10 ( ) 51 125 125 250 2 . 2= ________ 2 2 Based on comparing the computed to the rejection level which of the following is (are) true? A. We have statistically significant evidence at alpha=0.05 to show that H0 is false. B. Treatment and percent wound healing are not independent. Page 2 of 3 HLTH 501 C. Treatment and percent wound healing are independent. D. a and b. 3. A clinical trial is conducted comparing a new pain reliever for arthritis to a placebo. Participants are randomly assigned to receive the new treatment or a placebo and the outcome is pain relief within 30 minutes. The data are shown below. New Medication Placebo Pain Relief 44 21 No Pain Relief 76 99 Is there a significant difference in the proportions of patients reporting pain relief? Run the test at a 5% level of significance. Reject H0 if Z < ________ or if Z > ________ alpha= ________ = = ________ ________ = ________ Z = ________ Based on comparing the computed z to the rejection level z which of the following is (are) true? A. We have statistically significant evidence at alpha=0.05 to show that H0 is false. B. We have statistically significant evidence at alpha=0.05 to show that there a significant difference in the proportions of patients reporting pain relief. C. We do not have statistically significant evidence at alpha=0.05 to show there a significant difference in the proportions of patients reporting pain relief. D. a and b Page 3 of 3