Final Exam PrtScr Insert 1. In a study reported in the September 24, 2007, issue of the Archives of Internal + Medicine, German researchers described a study conducted on 1162 German adults suffering from chronic low-back pain. These subjects were randomly assigned to one of three groups: real acupuncture, sham acupuncture, and conventional therapy. Researchers found that 47% of subjects in the real acupuncture group improved, compared to 44% in the sham acupuncture group and 27% in the conventional therapy group. a. Identify the observational units in this study. b. Identify the explanatory variable. Also classify it as categorical or quantitative. If it is categorical, indicate whether it is binary. c. Identify the response variable. d. Is this an observational study or an experiment? Explain briefly. e. Are the percentages referenced in the study above parameters or statistics? ns of neonle2. Consider the following dot plots of ages for 3 groups of people. Group A Group B 20 Group Age (in years) a. Which group tends to have the oldest ages? b. Which group tends to have the youngest? c. Which group has the most consistency in ages? d. Which group has the least consistency in ages?5. Scores on the ver mean of 500 a 3. The following dotplot displays the salaries of the 23 presidents of California State University campuses for the 2007_08 academic year: 260,000 270,000 280,000 290,000 300,000 310,000 320,000 330,000 Salary (in dollars) These salaries, arranged in order, are listed here: 258,680 270,000 270,315 270,568 275,000 276,055 279,500 285,000 290,000 291,179 292,000 295,000 295,000 295,000 295,000 297,870 298,749 299,000 299,435 305,008 320,329 325,000 328,209 a. Determine the five number summary of these salaries. Consider the following outpus: Variable N Mean StDevsalary salary 291,822 17,669 b. The salary for Cal Poly's President Baker is $328,209. Calculate the z-score for his salary and decide whether his salary is more than two standard deviations above the mean.4. The table below shows the number of assignments (out of 30) completed in a Calculus I class. Student Assignments Completed a. What was the mean number of assignments completed? b. What was the median number of assignments completed? c. Find the lower and upper quartiles. d. If the number of assignments for student B were accidentally entered as 290, explain how this would affect the mean and the median. Do not actually calculate them. e. What proportion of students completed more than one half of the assignments