The Independent Variable and the Dependent Variable - Assignment Example

Week Assignment 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.- non variable b. Systolic blood pressure - variable c. Blood type – non variable d. The number of days in a week – non variable 2. For each of the following research questions, identify the independent variable and the dependent variable within each case (a through e): a. Does a person’s age affect psychological adjustment following burn injury? Age - Dependent variable Psychological adjustment -Independent variable b. How do physically handicapped children differ from non-handicapped children with respect to health concepts? State (handicapped or non-handicapped) – Dependent variable Health concepts – independent variable c. Do patients who administer their own pain medication have lower pain ratings than patients whose pain medication is administered by a nurse? Patients/nurse – dependent variable Amount of pain – independent variable d. Does the state a person lives in affect their weight? Person’s state – dependent variable Effect on weight – independent variable e. How does a bonnet compare to a stockinette in preventing heat loss in newborns? Bonnet/ stockinette – dependent variable Heat loss – independent variable 3. For each of the variables listed below, indicate which is discrete and which is continuous: a. Number of patients in an ICU ward - discrete b. Length of a chin implant - discrete c. HDL cholesterol reading - continuous d. Amount of time spent sleeping - continuous e. Body temperature measured in Fahrenheit - continuous f. Self-esteem as measured on a 10-question scale - continuous g. Number of conjoined twins born in a year in a hospital - discrete 4. For each of the variables listed below, indicate whether the measure is nominal, ordinal, interval, or ratio: a. Degrees, on the Celsius scale - interval b. Student’s class rank- ordinal c. Number of cancerous lymph nodes detected in a patient - ratio d. Respiratory rate - ratio e. Religious preference - nominal f. Military rank - ordinal g. Type of delivery (vaginal vs cesarean) - nominal h. IQ test score - ordinal 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. 3 3 4 1 0 2 0 1 2 0 4 0 0 3 2 6 0 0 0 1 0 2 1 0 1 1 3 2 1 0 1 3 1 1 0 4 6 7 0 1 Construct a frequency distribution for this set of data, showing the absolute frequencies, relative frequencies, and cumulative relative frequencies. Number of falls Absolute frequencies Relative frequencies Cumulative frequencies 0 13 0.325 13 1 11 0.275 24 2 5 0.125 29 3 5 0.125 34 4 3 0.075 37 5 0 0.000 37 6 2 0.050 39 7 1 0.025 40 6. 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? 67.5% b. What number of falls was the most frequent in this sample? 0 falls c. What number of falls was least frequent in this sample? 5 falls d. What percentage of residents had 2 or fewer falls? 75% e. What is the total size of the sample? 40 residents f. Are there any outliers in this data set? Yes 7. Would it be advantageous to group the data in Exercise 5 before constructing a frequency distribution? Why or why not? No, grouping the data would make the work more tedious and less accurate 8. 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? 9. 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 29 33 42 30 26 30 27 39 26 34 28 38 29 36 24 37 Mean – 30.37 Median – 29.00 Mode – 27.00 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. The distribution is skewed. 10. The following 10 data values are systolic blood pressure readings. Compute the mean, range, standard deviation, and variance for these data using StatCrunch. Copy and Paste your work from StatCrunch into your Word document submission. 130 125 160 120 170 120 150 140 160 140 11. For each blood pressure in Exercise 10, compute a Z score. Data point Mean Standard deviation Z score 120 141.5 17.04 -1.262 125 141.5 17.04 -0.968 140 141.5 17.04 -0.088 150 141.5 17.04 0.499 160 141.5 17.04 1.086 170 141.5 17.04 1.673 12. 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 Complied yes no no no Yes Yes no no no no yes yes no no no Experimental group Patient # 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Complied yes yes no yes yes yes no yes no no yes yes no no yes Using StatCrunch, construct a contingency table for these data, computing both row and column percentages for each of the four cells. Copy and Paste your StatCrunch table into your Word document submission. 13. Below are the values for diastolic and systolic blood pressure for 10 people: Diastolic: 90 80 90 78 76 78 80 70 76 74 Systolic: 130 126 140 118 114 112 120 110 114 116 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. 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. Below are Global carbon dioxide concentrations and the measured change in Global temperature (Temperature Anomaly) for an 11 year period in our recent past: YEAR CO2 Concentration (ppm) Temperature Anomaly (ºC) 1981 339.93 .043 1982 341.13 .022 1983 342.78 .097 1984 344.42 .074 1985 345.90 .091 1986 347.15 .066 1987 348.93 .267 1988 351.48 .155 1989 352.91 .267 1990 354.19 .509 1991 355.59 .430 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? Read More