The Usage of a Statistical Analysis - Assignment Example

Week Discussion and Assignment (Section) Due) Week Discussion How is statistical analysis used in your department or area of specialization? Be specific.  Statistical analysis is used to interpret collected data from a given survey. This helps to give exact findings in a comprehensive way which is easier to understand and to make appropriate policies. 2. Are statistics always true? Give an example (be specific) of how statistical analysis may be misused. What are the potential results and problems of such misuse of statistics? Statistics involves the entire process of collecting and analyzing data. This is a true process since it involves actual survey to obtain data for analysis. Collection of data could either be from primary or secondary source. Primary collection of data involves the use of questionnaire or interviews. This in turn gives first hand information required for the analysis. Statistical analysis may be misused in cases where secondary data is used. This refers to a situation in which data is obtained from either reference books or the internet. Secondary data is prone to alteration thus leading to wrong interpretation if data. Poorly analyzed data due to wrong information in turn lead to wrong formulation of policies which would cost the entire system. Week 1 Assignment 1. For each of the following, indicate which a variable is and which a constant is: a. Patients’ diastolic blood pressure - Variable b. The number of days in JULY - Constant c. Population of New York City - Variable d. The transcendental number pi (π) – (used in finding the circumference and area of a circle) - Constant 2. For each of the following research questions, identify the independent variable and the dependent variable: a. Do diabetes patients who choose their own diets have improved serum glucose levels than diabetes patients whose diets are selected by a nurse? Diabetes patient – Independent Variable Serum Glucose level – Dependent Variable b. How does instillation of a stent compare to lifestyle modification in preventing recurrence of coronary artery blockage? Instillation of a stent - Independent variable Reoccurrence of Coronary artery blockage – Dependent Variable c. Is the intracranial pressure of comatose patients affected by the presence of conversing visitors? Conversing Visitors - Independent Variable Intracranial Pressure of Comatose patients – Dependent Variable d. Does a person’s ethnicity affect recovery time following traumatic injury? A Person’s Ethnicity – Independent variable Recover time from traumatic injury – Dependent variable 3. For each of the variables listed below, indicate which is discrete and which is continuous: a. Amount of time spent sleeping - Continuous b. Weight in pounds - Discrete c. Number of pregnancies a woman has had - Discrete d. Number of MRI units in a city - Discrete 4. For each of the variables listed below, indicate whether the measure is nominal, ordinal, interval, or ratio: a. Military rank - Ordinal b. Number of cigarettes smoked daily - Nominal c. White blood cell count - Nominal d. Religious preference - Ordinal e. Degrees, on the Fahrenheit scale2 - Interval 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. 2 4 4 0 3 1 2 0 2 2 2 0 1 2 2 5 0 1 2 1 3 2 1 0 0 1 5 2 2 0 1 4 1 1 3 4 6 1 2 1 Calculate a frequency distribution for this set of data, showing the absolute frequencies, relative frequencies, and cumulative relative frequencies. Report all values. Number Absolute Frequency Relative frequency Cumulative frequency 0 7 0 7 1 11 11 18 2 12 6 30 3 3 1 33 4 4 1 37 5 2 0.4 39 6 1 0.12 40 Next, construct a histogram for this data set, including an overlay of a normal distribution. 14 12 10 8 6 4 2 0 1 2 3 4 5 6 7 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 or more falls? – 100% b. What number of falls was the most frequent in this sample? – 12 c. What number of falls was least frequent in this sample? – 1 fall d. What percentage of residents had 2 or fewer falls? – 83.33% e. What is the total size of the sample? - 40 7. The following set of numbers represents the scores of 30 psychiatric inpatients on a widely used measure of depression. 37 31 32 27 21 28 22 22 35 32 23 42 27 27 30 33 44 30 21 35 28 41 29 37 24 39 29 36 24 39 Calculate and report the following descriptive statistics:  Mean – 31.27  Median - 31  Mode - 27  Standard deviation – 4.8  Range - 23 If the values of the mean, median, and mode are not the same, discuss what this suggests about the shape of the distribution. Different values for mean, median and mode imply that the distribution is not evenly distributed. This is because the measures of central tendencies are not equal to the mean. 8. The following 20 data values are diastolic blood pressure readings. Compute the mean, range, standard deviation, and variance for these data. 140 120 110 130 180 100 110 160 190 120 130 150 140 160 140 90 120 180 170 160 Mean: ∑ values ÷ Frequency 2800 ÷ 20 = 140 Range: Maximum value – Minimum value 190 – 90 = 100 Standard deviation: √ (value - mean) ^ 2 = 4.47 Variance: ∑ (value – mean) ^ 2 = 2 9. For each blood pressure in Exercise 8, compute a Z score. Z score = (Mean – Midpoint) ÷ Standard Deviation = (140 – 100) ÷ 4.47 = 8.94 10. Below are the values for diastolic and systolic blood pressure for 10 people: Diastolic: 80 83 94 73 72 80 84 76 78 82 Systolic: 128 132 144 124 126 118 124 114 118 126  Construct a scatter plot (with appropriate axes that allow you to clearly visualize the data points) that shows the relationship between the two variables. 84 * 82 * 80 * 78 * 76 * 73 * 72 * 114 118 124 126 128 132 144  verbally describe the direction and magnitude of the relationship. The scatter plot above shows that more people with higher diastolic pressure experience low systolic pressure and vice versa.  Compute the correlation coefficient (Pearson’s r) to summarize the relationship for the data presented. How accurate was your description? Ŕ = [ n∑(x y) - ∑x ∑y] ÷ n√ (x^2) - ∑(x)^2 × √n∑(y^2) - ∑ (y)^2 = 3.13 References Dixon, W. J., & Massey, F. J. (1999). Introduction to statistical analysis (3d ed.). New York: McGraw-Hill. Top of Form Bottom of Form Read More