MARYVILLE SOSC341 Complete Course Latest 2022 July (Full)

SOSC341 Understanding Statistical Inference

Assignment   Z-Scores & Percent

 Assignment

The performance of 20 students on their final exam on statistics in 1992 and for the second class of 20 students in 2017 is shown in the table below.

Scores on statistics final exam, 1992 and 2017

Class of 1992      Class of 2017

80           100

91           99

91           94

80           94

74           94

74           88

73           88

75           81

76           88

73           89

73           80

69           88

67           76

68           75

68           63

68           61

68           53

57           55

58           56

59           82

 Use the data to answer the following questions.  NOTE:  You may need to use the z-score table located in Appendix A of the text (p. 697)

Find the mean and standard deviation for the final exam scores in the two years, 1992 and 2017.

Suppose you scored an 85 on this exam. In which distribution is your test score the farthest above the mean? How far above the mean is your score in both of these distributions?

Admission to a (paid) summer internship program requires that students earn a C or better (70% or higher) on their statistics final exam. If we assume that scores (in both years) on this test are reasonably normally distributed, what percentage of students in 1992 and 2017 would qualify for this internship?

 

SOSC341 Understanding Statistical Inference

Assignment   Mean, Median, Mode, & Skewness

Assignment

Find the mean, median, and mode for the following data:

ALL WORK MUST BE SHOWN TO RECEIVE CREDIT

5, 7, 3, 8, 2, 3, 3, 1, 9

104, 139, 145, 150, 167, 205, 205, 20

See Stem and Leaf Plot below:

Stem     Leaf

1              0,3,5,5

2              0,1,4,7,7,7,7,8,8,9

3              3,3,5,8,9

4              0,1

5              7,8,8,8,9,9

 

SOSC341 Understanding Statistical Inference

Assignment   Variance & Standard Deviation

Assignment

Several studies (Keinan, 2002, for example) have found evidence that belief in magic and luck increased as stress levels increased. The more stressed people were, the more likely they were to engage in magical thinking. Suppose you did your own study examining the relationship between test anxiety and belief in the power of a lucky charm. You ask one group of students to bring their own personal lucky charm to their statistics final exam. Another group is the control group and has to take their statistics exam without any lucky objects present during the test.

Scores on statistics final exam with and without a lucky charm

Without Lucky Charm     With Lucky Charm

82           64

95           38

68           100

75           42

70           77

70           100

79           97

79           99

76           95

76           48

 Use the data to answer the following questions:

Calculate the mean for each group.

Calculate the standard deviation for each group.

In your opinion, does having a lucky charm result in better performance on the exam? How do the two groups differ? How are they similar?

 

SOSC341 Understanding Statistical Inference

Assignment   Frequency Tables & Grouped Frequency Tables

Assignment

In a senior research class, several students decided to see if the perception of the passage of time was influenced by age. They asked volunteers to participate in a time estimation task. Participants were first asked their age. Then, they were told that as soon as a green light flashed on the computer monitor in front of them, they were to begin estimating a 27-second time interval, without counting or using any kind of timing device. As soon as the participant felt that the indicated interval had passed, she or he pressed the space bar on the keyboard. The actual duration of the time interval that had passed was then presented on the monitor, followed by a warning tone and the next trial. The table below shows the mean errors (in milliseconds) made by the participants for each time interval. Positive errors indicate an overestimation of the time interval, and negative errors indicate an underestimation of the time interval. Participants in age group 1 were between 10 and 21 years of age. Participants in age group 2 were over the age of 50.

Time-estimation errors (in milliseconds) by age

ID            Age Group          Error      ID            Age Group          Error

1              1              9.00        11           2              -3.00

2              1              13.00     12           2              3.00

3              1              13.00     13           2              7.00

4              1              1.00        14           2              4.00

5              1              5.00        15           2              5.00

6              1              -11.00    16           2              5.00

7              1              11.00     17           2              10.00

8              1              1.00        18           2              1.00

9              1              -1.00      19           2              11.00

10           1              -16.00    20           2              14.00

 Use the data shown in the table above to Construct TWO grouped frequency distributions, one for each Age Group of Data.  You’ll need to determine how big your intervals should be and where they will start).  Include relative and cumulative frequency distributions for each age group.  Table 2.31 on p. 56 of the text can be used as an example of what to include in a grouped frequency table. 

Then, use the data from your grouped frequency distributions to answer the following questions:

What percentage of over-50-year-olds made errors of 5 milliseconds or less?

How many of the participants in age group 1 made underestimations of the time interval?

How many of the over-50-year-olds made underestimations? iv)    How many participants (considering both groups) made overestimations?

 

SOSC341 Understanding Statistical Inference

Assignment   Histograms & Other Graphs

Assignment

Students in an introductory psychology course were asked to participate in an experiment examining the relationship between quality of sleep and perceived stress. Each student in the class kept track of the quality of his or her sleep for seven consecutive days using a 5-point scale where 1 indicated very poor quality, 3 indicated average quality, and 5 indicated excellent sleep quality for the previous night. At the end of the week, each student donated a small hair sample consisting of approximately 20 to 30 strands of hair. The level of cortisol in the hair sample was obtained (in nanograms per gram of hair). Higher levels of cortisol indicate higher levels of stress. The table below shows the raw data from the 50 students in the study.

Hair cortisol level (in ng/g) and sleep quality ratings (1-5)

ID            Sleep Quality     Cortisol ID            Sleep Quality     Cortisol ID            Sleep Quality     Cortisol ID            Sleep Quality                Cortisol

1              3              136         16           4              103         31           3              79           46           1              35

2              3              74           17           4              31           32           2              105         47           5              166

3              3              143         18           4              81           33           3              145         48           5              83

4              4              137         19           4              97           34           1              48           49           1              165

5              1              107         20           2              151         35           1              194         50           2              51

6              2              136         21           3              140         36           2              174                                        

7              1              151         22           4              97           37           2              99                                          

8              1              177         23           4              109         38           2              28                                          

9              5              140         24           3              199         39           4              130                                        

10           3              61           25           3              69           40           4              148                                        

11           2              41           26           4              26           41           5              179                                        

12           5              189         27           1              112         42           5              189                                        

13           2              79           28           3              201         43           3              129                                        

14           2              43           29           2              34           44           2              80                                          

15           2              170         30           2              110         45           1              79                                          

 Use the data to answer the following questions:

Create frequency distributions of both the sleep quality and cortisol levels.

Draw a graph showing the distribution of sleep quality in the sample.

Draw a graph showing the distribution of cortisol in the hair sample.

 

SOSC341 Understanding Statistical Inference

Assignment   Data Scales & the Ordinal Data Debate

Read an article that interests you and then, in a paragraph, answers the following questions about that article:

What were the independent and dependent variables in the study you read? [Remember, the independent variable (described in your text), is the variable that is manipulated or that created groups or that we think influences another variable, the dependent variable. The dependent variable is a variable we measure to see the effect of the independent variable].

What were the authors trying to show in their article (In other words, what was the context of the study they are reporting on)?

What was the most important result of the study (Or, what was the authors’ “take-home” message)?

 

SOSC341 Understanding Statistical Inference

Assignment   Probability

Assignment

In a 1985 study, Breslow (cited in Hand et al., 1994) examined the death rates from coronary heart disease in a set of British male physicians. He also classified the doctors according to whether or not they smoked cigarettes. The table below shows the number of physicians who died from coronary heart disease.

Age, smoking, and heart disease in a sample of male physicians

Age (in years)    Nonsmokers      Smokers

35-44     2              32

45-54     12           104

55-64     28           206

65-74     28           186

75-84     31           102

 Use the data to answer the following questions:

How many doctors were surveyed?

How many of these doctors reported that they smoked? How many reported that they did not smoke?

 

SOSC341 Understanding Statistical Inference

Assignment Hypothesis Testing/Central-Limit Theorem

Assignment

In a classic study of human memory, Elizabeth Loftus (1975) asked two groups of subjects to watch a very short film of a traffic accident (the film itself lasts less than a minute, and the accident only a few seconds). In the film, a car runs a stop sign into oncoming traffic, ultimately causing a five-car, chain-reaction accident.

The two groups were then given a questionnaire with 10 questions on it. For each group, only two questions were targets; the rest were just filler. For Group 1, the first target question was “How fast was car A (the car that ran the stop sign) going when it ran the stop sign?” Group 2 was asked: “How fast was car A going when it turned right?” Both groups received the same final question on the form, which was “Did you see the stop sign for car A?”

For the target question about the speed of the car.  Consider what the study is measuring (the dependent variable)

The null hypothesis (in words) would be:

The alternative hypothesis (in words) would be:

The null and alternative (in symbols) would be:

Null =

Alternative = ____________________.

 For each of the following samples, use the available information to calculate (where possible) or predict the following statistics:

 (standard deviation)

For all three samples,

 

SOSC341 Understanding Statistical Inference

Assignment   The Z-test

Assignment

An educational psychologist is interested in seeing if Return To College (RTC) students—that is, students who have not attended school for more than 4 years in order to work or raise a family—are more motivated to achieve higher grades than students who have not taken a break in their education. She knows that the distribution of grade point averages (GPAs) for students at her college who have not interrupted their education is normally distributed with a mean of 2.90 and a standard deviation of 0.89. She collects the following sample of GPAs for 10 RTC students. Use the data in Table 9.6 to answer the following questions.

GPA for RTC Students

GPA

3.70

2.60

3.10

3.00

3.10

3.80

2.60

3.40

3.00

2.80

 Use the data to answer the following questions:

Find the mean GPA for the RTC students in the sample.

Determine the null and alternative hypotheses.

**Decide if the GPAs earned by RTC students are significantly higher than the population.

**Question C was modified from the original question in the text on p. 380

 

SOSC341 Understanding Statistical Inference

Assignment  Midterm Project

As you begin to think about questions more critically, the next step is to apply what you have learned in developing sound research questions. As such, the midterm project is formed to help you think about how to do this. Using one of the data sets provided, you are being asked to describe the data and sample using statistics and visualization, to develop and test a hypothesis, and to report the results in APA style.  To do this you will need to create a report after completing each major bullet point below.  Here is a link to a template that you might use as a guide in developing this project. 

Midterm Project Template.docx

Review the videos in your Module Resources and Tutorials 4 before completing this project.

Please Note:

All data sets and/or resources needed for this project are linked at the bottom of the page.

Project Details

Your submission for the Midterm Project should be a Jamovi file with a .omv extension AND a document with the information outlined below:

A.    Select one of the datasets provided.

B.    Create two hypotheses.

 

SOSC341 Understanding Statistical Inference

Assignment  ANOVA Worksheet

Name:___________________________

ANOVA Worksheet

To answer the questions, do the following steps:

1)Complete the table

2) Find the Critical F

3) Compare your F to the Critical F

Question 1: Ellie wants to know if student involvement influences GPA. Her 24 students fit into one of 3 groups (not involved, somewhat involved, and very involved). Is the test significant?

                Sum of Squares