SPSS Homework Central Tendency Template

PSYC 354 SPSS H OMEWORK : C ENTRAL T ENDENCY T EMPLATE Problem Set 1: A neuropsychologist assesses the cognitive functioning of 17 adults who are at- risk for Alzheimer’s disease using the Mini-Mental State Examination (MMSE). Scores higher than 24 indicate better cognitive functioning, while scores lower than 24 indicate worse functioning and possible early-stage Alzheimer’s disease. The scores are contained in the table below. Remember to put your initials within any and all variable names. MMSE Scores 26 29 29 8 29 24 10 28 28 27 29 28 27 26 30 29 26 1. Using the data in the table above, set up a data file in SPSS and create a table of descriptive statistics using the “Explore” command. Paste the table here: (8 pts) Descriptives Statistic Std. Error Scores Mean 25.4706 1.55090 95% Confidence Interval for Mean Lower Bound 22.1828 Upper Bound 28.7583 5% Trimmed Mean 26.1895 Median 28.0000 Variance 40.890 Page 1 of 8

PSYC 354 Std. Deviation 6.39451 Minimum 8.00 Maximum 30.00 Range 22.00 Interquartile Range 3.00 Skewness -2.349 .550 Kurtosis 4.610 1.063 2. Using the same data, create a histogram showing the distribution of MMSE scores in the sample. Paste the histogram here: (7 pts) 3. List the mean and the median for MMSE scores. (4 pts) Mean = 25.4706, Median = 28.00 4. Based on the information in numbers 1-3, which measure of central tendency would you use to describe this data set? Support your answer with material from the presentations and/or reading this week. (6 pts) Based on the examples provided in the presentation, the most suitable measure of central tendency to describe this data set would be the median. The median is the ideal measure Page 2 of 8

PSYC 354 2 2 2 2 2 2 6 5 8 9 10 6 1. Using the data in the table above, set up your data file in SPSS and create one table of Descriptive Statistics using the “Explore” function that shows descriptives for narcissism split by group (ASPD and no ASPD separately). Paste the table here: (7 pts) Descriptives DIagnosis Statistic Std. Error Scores ASPD Mean 26.2000 3.94067 95% Confidence Interval for Mean Lower Bound 17.2856 Upper Bound 35.1144 5% Trimmed Mean 27.0556 Median 31.0000 Variance 155.289 Std. Deviation 12.46150 Minimum 2.00 Maximum 35.00 Range 33.00 Interquartile Range 12.00 Skewness -1.631 .687 Kurtosis 1.131 1.334 no ASPD Mean 8.8000 .84063 95% Confidence Interval for Mean Lower Bound 6.8984 Upper Bound 10.7016 5% Trimmed Mean 8.8333 Median 8.5000 Variance 7.067 Std. Deviation 2.65832 Minimum 5.00 Page 4 of 8

PSYC 354 Maximum 12.00 Range 7.00 Interquartile Range 6.00 Skewness .002 .687 Kurtosis -1.503 1.334 2. What is the standard deviation for the ASPD group in this sample? (5 pts) The standard deviation for the ASPD group is 12.46150 3. Compare the means of each group (ASPD and no ASPD). What can you say about the narcissism scores of the ASPD group compared to the no ASPD group? (5 pts) The ASPD group has a significantly higher mean narcissism score (26.2000) compared to the no ASPD group (8.8000). The substantial difference in mean scores suggests that, on average, individuals in the ASPD group have higher narcissism scores compared to those in the no ASPD group. This indicates that there may be a strong association between ASPD and higher narcissism scores in this sample. 4. Using the same data, create a boxplot in SPSS to show the difference in narcissism scores between the two diagnostic groups. Paste the boxplot here: (7 pts) Page 5 of 8

PSYC 354 References Liberty University. (n.d.). SPSS homework tutorial: Describing and graphing central tendency for groups. [Video]. https://canvas.liberty.edu/courses/521042/pages/watch-spss- homework-tutorial-describing-and-graphing-central-tendency? module_item_id=59795748 Page 7 of 8

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