Homework 1

BST322 – HOMEWORK #1 Name: Creancy, Cyrus ___________________ Directions: (a) Enter all your answers into this Word document and submit the entire document. IMPORTANT: The name of your Word document MUST begin with your LAST NAME. (b) When you use Statcrunch to calculate an answer, copy and paste the results into this document. (c) For questions with answer spaces identified, please enter your answers in those spaces. (d) While putting your answers in a different color font is helpful, please DO NOT use red font since this is the color used to provide feedback on your answers. 1. Each of the following 4 examples describes either a variable or a constant , indicate which is a variable and which is a constant : [1 point each, total 4 points] a. The number of minutes in an hour b. Patients’ systolic blood pressure c. Pi (π) e.g., for finding the circumference of a circle d. College students’ level of depression ANS. a. constant b. variable c. constant d. variable 2. For each of the following research questions, identify the independent variable (IV) and the dependent variable (DV). 3 points each, total 15 points] a. Does a person’s age affect psychological adjustment following a burn injury? b. How do physically handicapped children differ from non-handicapped children with respect to health concepts? c. Do patients who administer their own pain medication have lower pain ratings than patients whose pain medication is administered by a nurse? d. Is the intracranial pressure of comatose patients affected by the presence of conversing visitors? e. How does a bonnet compare to a stockinette in preventing heat loss in newborns? ANS. a. IV: psychological adjustment DV: age b. IV: health concepts DV: physical condition c. IV: pain ratings DV: patients with pain d. IV: intracranial pressure DV: presence of conversing visitors e. IV: heat loss in newborns

DV: type of head covering 3. For each of the variables listed below, indicate which is discrete and which is continuous : [1 point each, total 6 points] a. Number of beds in a hospital. b. Height in inches c. Number of pregnancies a woman has had d. Amount of time spent sleeping e. Body temperature measured in Fahrenheit f. Self-esteem as measured on a 10-question scale ANS. a. discrete b. discrete c. discrete d. discrete e. continuous f. continuous 4. For each of the variables listed below, indicate whether the measure is nominal, ordinal, interval, or ratio: [2 points each, total 14 points] a. Degrees, on the Celsius scale b. Student’s class rank (1 st , 2 nd , 3 rd ) c. Number of cigarettes smoked daily d. Religious preference e. Military rank f. Type of delivery (vaginal vs. cesarean) g. White blood cell count ANS. a. interval b. ordinal c. ratio d. nominal e. ordinal f. nominal g. ratio 5. The following data represent the number of times that a sample of residents in nursing homes who were aged 80 or older fell during a 12-month period. Construct a frequency distribution for these data, showing the absolute frequencies, relative frequencies, and cumulative relative frequencies . [10 points] 0 3 4 1 0 2 0 1 2 0 1 0 0 1 2 5 0 1 0 1

No, this is a small data set so it wouldn’t be helpful to group the data. If the data set was larger then grouping the data would make it easier to look through faster. 8. Referring back to the data in Exercise #5: a. Draw a graph of the frequency distribution of the data using StatCrunch. [6 points] b. Describe the shape of the frequency distribution in terms of modality and skewness. [2 points] ANS: the distribution is bimodal and is negatively skewed due to patients having at least 0-1 fall in the last 12 months. c. Is the number of falls normally distributed? [2 points] ANS: no, due to the big difference in patients falls.

9. The following set of numbers represent the scores of 30 psychiatric inpatients on a widely-used measure of depression. 41 27 32 24 21 28 22 25 35 27 31 40 23 27 29 33 42 30 26 30 27 39 26 34 28 38 29 36 24 37 a. What are the mean, median, and mode for these data? [6 points] b. If the values of the mean, median, and mode are not the same, discuss what this suggests about the shape of this distribution. [3 points] c. Construct a graph of the distribution of these data using StatCrunch to prove your point. [5 points] ANS. a. Summary statistics: Column Mean MedianMode depression30.366667 29 27 b. patients with the depression levels of 25 to 30 are the most common.