BST 322 Week 1 Assignment

1. (1 pt) For each of the following (a through d), indicate which is a variable and which is a constant:

a.       The number of minutes in an hour.

b.      Systolic blood pressure.

c.       Freezing temperature of water in degrees Kelvin.

d.      Ratings of daily anxiety.

2. (1 pt) For each of the following research questions, identify the independent variable and the dependent variable within each case (a through d):

1. Does a person’s age affect psychological adjustment following burn injury?
2. How do physically handicapped children differ from nonhandicapped children with respect to health concepts?
3. Do patients with a family support system in place have lower pain ratings than patients with no              family support system in place?
4. Is the intracranial pressure of comatose patients affected by acupuncture treatments?

3. (1 pt) For each of the variables listed below, indicate which is discrete and which is continuous:

a.       Number of patients in an ICU ward

b.      Length of a chin implant

c.       Number of hospital beds in a step down facility

d.      Tidal volume, measured in mLs, of a patient recovering from surgery

4. (2 pts) For each of the variables listed below, indicate whether the measure is nominal, ordinal, interval, or ratio:

a.       Degrees, on the Celsius scale

b.      Student’s class rank

c.       Ratings of a hospital based on care surveys ranked as “Poor, Fine, Good, Exceptional”

d.      Survival 5 years out after surgery (yes/no)

e.       Average cholesterol level of a group of control patients in a study

f.       Settings of tick exposure for Lyme disease designated as “Woodland, Park, City, Suburb”

g.      HDL Cholesterol levels

h.      Faculty rank (Clinical Assistant Professor, Associate Professor, Full Professor)

5. (2 pts) 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.

            3          3          4          1          1          2          1          1          2          0

            4          1          0          3          2          6          1          0          0          1

            0          1          1          1          1          1          3          2          1          0

            1          3          1          1          0          4          6          9          0          1

Construct a frequency distribution table for this set of data in StatCrunch, showing the absolute frequencies, relative frequencies, and cumulative relative frequencies. Would it be advantageous to group the data before constructing a frequency distribution? Why or why not?  Construct a Summary Statistics table in StatCrunch to list the n, mean, mode, Skewness and Kurtosis of the data. Paste your work from StatCrunch into your assignment.

6. (1 pt) Using information from the frequency distribution in Exercise 5, answer the following:

a.       What percentage of the nursing home residents had at least 1 fall?

b.      What number of falls was the most frequent in this sample?

c.       What number of falls was least frequent in this sample?

d.      What percentage of residents had 2 or fewer falls?

7. (1 pts) Draw a graphic of the frequency distribution of the data in Exercise 5 using StatCrunch.  Copy and Paste your graphic from StatCrunch into your Word document submission.  Describe the shape of the frequency distribution in terms of modality and skewness.  Is the number of falls normally distributed?

8. (2 pts) Draw a graphic (bar graph and a pie chart) of the “marital” status of the data set from Week 1’s Discussion question 2 using StatCrunch (the excel file is named “Week 1 Discussion Question 2 Data”).  You can also find the file in the “Course Resources” area. Construct a frequency distribution table (showing the absolute frequencies, relative frequencies, and cumulative relative frequencies for marital status). What percentage of the participants are married? Is it meaningful to calculate the cumulative frequency with this data set?  Why or why not? Copy and Paste your graphics (including the frequency table) from StatCrunch into your Word document submission. 

9. (1 pt) The following set of numbers represent the scores of 30 psychiatric inpatients on a widely used measure of depression.  What are the mean, median, and mode for these data?

                        41        27        32        24        21        28        22        25        35        27

                        31        40        23        27        39        33        42        30        46        30

                        27        39        26        34        48        38        29        36        24        37

If the values of the mean, median, and mode are not the same, discuss what this suggests about the shape of the distribution.  Construct a Graphic of the distribution of this data using StatCrunch to prove your point.  Copy and Paste your graphic from StatCrunch into your Word document submission.

10. (1 pt) The following 10 data values are systolic blood pressure readings.  Compute the mean, range, standard deviation, Q1, Q3, IQR and variance for these data using StatCrunch.  Are there any outliers in this data set?  Plot a boxplot to prove your answer.  Copy and Paste your work from StatCrunch into your Word document submission.

                        130      125      160      120      170

                        120      130      130      140      90

11. (1 pt) For each blood pressure in Exercise 10 above, compute a Z score.

12. (2 pts) The following data designate whether patients in two groups (experimental and control) complied with a medication regimen. The experimental group participated in an intervention designed to promote perceived mastery over health events:

              Control group

Patient #

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

Complied

yes

no

no

no

yes

yes

no

no

no

no

no

yes

no

no

no

yes

              Experimental group

Patient #

17

18

19

20

21

22

23

24

25

26

27

28

29

30

Complied

yes

no

yes

yes

yes

no

no

no

no

yes

yes

yes

no

yes

            Using StatCrunch, construct a contingency table for these data, computing both row and column percentages, with totals and all labels for each of the four cells and totals. Copy and Paste your StatCrunch table into your Word document submission.

13. (1 pts) Below are the values for diastolic and systolic blood pressure for 10 people:

            Diastolic:         90     80     90     78     76     88    80     70     76     74

            Systolic:        130   126   140   118   114   112   120   110   114   136

            Using StatCrunch, construct a scatterplot that shows the relationship between the two variables.  Copy and Paste your work from StatCrunch into your Word document submission. Verbally describe the direction and magnitude of the relationship.

14. (1 pt) Compute the correlation coefficient (Pearson’s r) in StatCrunch to summarize the relationship for the data presented in Exercise 13.  How accurate was your description?     

15. (2 pts) Below are Global carbon dioxide concentrations and the measured change in Global temperature (Temperature Anomaly) for a period in our recent past:

YEAR

CO₂  Concentration (ppm)

Temperature Anomaly (ºC)

1981

339.93

.043

1985

343.13

.098

1989

350.17

.211

1992

355.25

.368

1995

360.15

.410

1999

364.05

.566

2002

372.01

.625

2005

380.14

.714

2009

384.12

.885

2012

399.21

1.07

2017

419.12

1.20

Using StatCrunch, construct a scatterplot that shows the relationship between the two variables (carbon dioxide concentrations and the measured change in Global temperature). Calculate the r value using StatCrunch.  Copy and Paste your work from StatCrunch into your Word document submission. Verbally describe the direction and magnitude of the relationship you find.  What does this tell you about Global warming?