# Histograms And Descriptive Statistics

Preparation

This assessment has three parts, each of which is described below. Submit all three parts as Word documents.

Note: All the course documents you will need for the assessment are linked in the Resources section.

Read Assessment 1 Context to learn about the concepts used in this assessment.

This assessment uses the grades.sav file, found in the Resources for this assessment.

The fictional data in the grades.sav file represent a teacher’s recording of student demographics and performance on quizzes and a final exam across three sections of the course. Each section consists of about 35 students (N = 105).

There are 21 variables in grades.sav. To prepare for this assessment, complete the following:

Open your grades.sav file and navigate to the “Variable View” tab.

Read the Data Set Instructions, and make sure you have the correct Values and Scales of Measurement assigned.

Part 1: Histograms and Descriptive Statistics

Your first IBM SSPS assessment includes two sections:

Create two histograms and provide interpretations.

Calculate measures of central tendency and dispersion and provide interpretations.

Key Details and Instructions

Submit your assessment as an attached Word document.

Begin your assessment by creating a properly formatted APA title page. Include a reference list at the end of the document if necessary. On page 2, begin Section 1.

Organize the narrative report with your SPSS output charts and tables integrated along with your responses to the specific requirements listed for that assessment. (See the Copy/Export Output Instructions in the Resources for instructions on how to do this.)

Label all tables and graphs in a manner consistent with APA style and formatting guidelines. Citations, if needed, should be included in the text as well as a reference section at the end of the report.

For additional help in completing this assessment, refer to IBM SPSS Step-By-Step Instructions: Histograms and Descriptive Statistics, linked in the Resources.

Section 1: Histograms and Visual Interpretation

Section 1 will include one histogram of “total” scores for all the males in the data set, and one histogram of “total” scores for all the females in the data set.

Create two histograms using the total and gender variables in your grades.sav data set:

A histogram for male students.

A histogram for female students.

Below the histograms, provide an interpretation based on your visual inspection. Correctly use all of the following terms in your discussion:

Skew.

Kurtosis.

Outlier.

Symmetry.

Modality.

Comment on any differences between males and females regarding their total scores. Analyze the strengths and limitations of visually interpreting histograms.

Section 2: Calculate and Interpret Measures of Central Tendency and Dispersion

Using the grades.sav file, compute descriptive statistics, including mean, standard deviation, skewness, and kurtosis for the following variables:

id.

gender.

ethnicity.

gpa.

quiz3.

total.

Below the Descriptives table, complete the following:

Indicate which variable or variables are meaningless to interpret in terms of mean, standard deviation, skewness, and kurtosis. Justify your decision.

Next, indicate which variable or variables are meaningful to interpret. Justify your decision. For meaningful variables, specify any variables that are in the ideal range for both skewness and kurtosis.

Specify any variables that are acceptable but not excellent.

Specify any variables that are unacceptable. Explain your decisions.

For all meaningful variables, report and interpret the descriptive statistics (mean, standard deviation, skewness, and kurtosis).

Part 2: Data Screening

For this part of the assessment, respond to the following questions:

What are the goals of data screening? How can you identify and remedy the following?

Errors in data entry.

Outliers.

Missing data.

Part 3: z Scores, Type I and II Error, Null Hypothesis Testing

This IBM SPSS assessment includes three sections:

Generate z scores for a variable in grades.sav and report/interpret them.

Analyze cases of Type I and Type II error.

Analyze cases to either reject or not reject a null hypothesis.

The format of this assessment should be narrative with supporting statistical output (table and graphs) integrated into the narrative in the appropriate place (not all at the end of the document). See the Copy/Export Output Instructions for instructions on how to do this.

Download the z Scores, Type I and Type II Error, Null Hypothesis Testing Answer Template from the Required Resources, and use the template to complete the following sections:

Section 1: z Scores in SPSS.

Section 2: Case Studies of Type I and Type II Error.

Section 3: Case Studies of Null Hypothesis Testing.