Name two measures of the variation of a distribution, and state the conditions under which each measure is preferred for measuring the variability of a single data set. Select all that apply. E] A. The interquartile range is preferred when there are few data points. I:] B. The standard deviation is preferred when the data is relatively symmetric. E] C. The mean is preferred when the data is relatively symmetric. E] D. The standard deviation is preferred when there are many data points. E] E. The interquartile range is preferred when the data is strongly skewed or has outliers. E] F. The z-score is preferred when there are many data points. I] G. The median is preferred when the data is strongly skewed or has outliers. E] H. The median is preferred when when the data is relatively symmetric. The data were collected from a statistics class. The column heads give the variable, and each of the rows represents a student in the class. How many variables are there? Eye Shoe Height Weight Number College Units There are El variables. (Type a whole number.) Indicate whether the study is an observational study or a controlled experiment. Patients with multiple sclerosis are randomly assigned a new drug or placebo and are then given a test of coordination after six months. (E Choose the correct answer below. 0 A. This is a controlled experiment because the patients chose whether they took the drug or the placebo. O B. This is an observational study because the patients chose whether they took the drug or the placebo. O c. This is an observational study because the patients were assigned drugs by those conducting the study. 0 D. This is a controlled experiment because the patients were assigned drugs by those conducting the study. - . H ' ht ' h d The dotplot shows heights of college women, eganggfd 3%)\"? a the mean is 64 inches (5 feet 4 inches) and the standard deviation is 3 inches. Complete parts a and b below. 55 58 6164 67 70 73 -3-2-1012 3 a. What is the zscore for a height of 61 inches (5 feet 1 inch)? D b. What is the height of a woman with a z-score of 3? D inches