Assessment Description

Descriptive Statistics Project Directions: Use the following information to complete the questions below. A researcher was interested in the anxiety present in students just prior to the midterm exam. The researcher used an anxiety self-quiz to gauge students' anxiety. The scores for 30 students are given here. 1.Use SPSS to calculate the numerical descriptive statistics mean, median, standard deviation, and variance of the anxiety scores. Utilizing Excell the mean was calculated at 71.2333, the median was calculated at 70 and the standard deviation (sample) was calculated at 17.58268. 2.Construct a frequency table with class, frequency, relative percent, and cumulative percent that has 6 classes to describe the distribution of the data in SPSS. Min =40 Max=99 Range 59/6=9.83. Rounded to 10 3.Use the frequency table to construct a histogram in SPSS. A=data B=M,M,SD, C=High and Low Range? D=ranges E=bins F= frequency

Review Questions Chapter 1, number 1.8 Vocabulary  Independent Variable : This is what you change on purpose to see if it makes something else happen. Think of it as the cause in a cause-and-effect experiment.  Confounding Variables : These are the sneaky variables that mess with your results without you realizing it. They might trick you into thinking your independent variable caused an effect, but actually, these other variables did.  Dependent Variable : This is what you measure or watch to see if it changes when you mess with the independent variable. It's the effect in a cause-and-effect experiment.

GRE test-taking workshop or a control (non-test-taking) workshop and then compares the GRE scores earned subsequently by the two groups of students. o Experiment o Independent Variable – test taking workshop versus non test taking workshop o Confounding – anxiety levels, current life circumstances, rest  A social scientist wishes to determine whether there is a relationship between the attractiveness scores (on a 100-point scale) assigned to college students by a panel of peers and their scores on a paper-and-pencil test of anxiety. o Observational study  A political scientist wishes to determine whether males and females differ with respect to their attitudes toward defense spending by the federal government. She asks each person if he or she thinks that the current level of defense spending should be increased, remain the same, or be decreased. o Observational study  Investigators found that four year-old children who delayed eating one marshmallow in order to eat two marshmallows later, scored higher than non-delayers on the Scholastic Aptitude Test (SAT) taken over a decade later. o Observational study Chapter 2, number 2.14 Personal Notes  Frequency distribution- helps us detect data patterns. It is a collection of observations produced by sorting observations into classes and showing their frequency of occurrence in each class. o For Quantitative data o In the table numbers from lowers to highest (column)  Distribution Group Data – observations are sorted into classes of more than one value o W:240-249 and F: 1 o W:230-239 and F: 0 TABLE 2.1 (book) Then place a short vertical stroke or tally next to a number each time its value appears in the original set of data; once this process has been completed, substitute for each tally count. To do: Construct a frequency distribution for the number of different residences occupied by graduating seniors during their college career, namely 1,4,2,3,3,1,6,7,4,3,3,9,2,4,2,2,3,2,3,4,4,2,3,3,5 What is the shape of this distribution? The shape of this distribution is positively skewed Number of Residents Frequency 1 2 2 6

3 8 4 5 5 1 6 1 7 1 8 1 9 1 Chapter 3, numbers 3.10 and 3.17 Personal Notes  Mode - the value of the most frequent score  The median is the middle number in a sorted list of numbers. o Sort the numbers from smallest to largest. o If there's an odd number of entries, the median is the middle one. o If there's an even number of entries, the median is the average of the two middle numbers.  For an odd number of entries example, given the numbers [7, 5, 3, 8, 9], we sort them to get [3, 5, 7, 8, 9]. The median is the middle number, which is 7 .  For an even number of entries example, given the numbers [7, 5, 3, 8], we sort them to get [3, 5, 7, 8]. The median is the average of the two middle numbers, (5 + 7) / 2, which is 6.0 .  Mean – add all the cores and dive by the number of scores. o Mean = sum of all scores/number of scores  Population - a complete set of scores  Sample- a subset of scores 3.10 During their first swim through a water maze, 15 laboratory rats made the following number of errors (blind alleyway entrances): 2, 17, 5, 3, 28, 7, 5, 8, 5, 6, 2, 12, 10, 4, 3. Find the mode, median, and mean for these data. Mode: 5 Median: 2 , 2, 3, 3, 4, 5, 5, 5, 6, 7, 8, 10, 12, 17 , 28 .  The Median is 5 Mean: 117/15 = 7.8 Without constructing a frequency distribution or graph, would you characterize the shape of this distribution as balanced, positively skewed, or negatively skewed? I believe the shape of this distribution will be positively skewed because most of the data concentrates towards the left side of the graph as I visualize and analyze the numbers ( Witte & Witte, 2017). Chapter 4, numbers 4.17 and 4.19 Measure of Variability is the number of scores dispersed or scattered in a distribution.