# Part 1: Generate and Organize a Set of Random Data Values

**Application 3: Inferential Statistics **

The completed application should be submitted as a single document

Purpose: The purpose of this assignment is to collect and organize a random sample of data values and then create two different confidence interval estimates of the population mean. The information will then be analyzed in a written summary.

## Part 1: Generate and Organize a Set of Random Data Values

Methods: Use Excel (or similar software) to create the tables. Then copy the items and paste them into a Word document. The tables should be formatted vertically, have borders, and be given the labels and titles stated in the assignment. The proper symbols should be used. Do not submit this assignment as an Excel file. The completed assignment should be a Word document.

**If you have completed Application 1 successfully, you can use the data and statistics from that application to complete steps 1 and 2 below. Otherwise start with step 1. **

1. The sample data will be found by using an online random number generator. Use the link below or any other random generator of your choice.

Set the random number generator to find numbers between 1 and 75. Repeat the simulation 40 times, recording the number for each repetition. Use technology (Excel, graphing calculator, etc.) to sort the data from low to high. Use Excel or similar software to put the data into a table with 4 columns and 10 rows. Label this “Table 1: Sorted Set of Random Data.”

2. Use technology to find the mean and standard deviation. Put the mean, standard deviation, and sample size into a table with the proper symbol in the left column and the value of the statistic in the right column. The statistics should be rounded properly. Label this “Table 2: Important Statistics.”

3. Choose a confidence level similar to one found in the homework (such as 90%, 95% or 99%). Based on the confidence level, find the critical value and calculate the margin of error. In a table, state the first confidence level, the point estimate, the critical value, margin of error, and confidence interval. Put the proper symbols or term in the left column and the value of the statistic or properly formatted confidence interval in the right column. The statistics and confidence interval should be rounded properly. Label this “Table 3: Confidence Interval 1.”

4. Choose another confidence level similar to one found in the homework. Based on the second confidence level, find the critical value and calculate the margin of error. In a table, state the second confidence level, the point estimate, the critical value, margin of error, and confidence interval. Put the proper symbols or term in the left column and the value of the statistic or properly formatted confidence interval in the right column. The statistics and confidence interval should be rounded properly. Label this “Table 4: Confidence Interval 2.”

## Part 2: Written Introduction and Summary

1. Write an introduction to this application. Discuss how the data values were found and why they are random. Describe the basic components of the application and the statistical concepts that will be applied. The introduction should be at least 50 words and be written with proper grammar and spelling.

2. Write a summary of the application, considering the following topics. The summary should be at least 150 words and be written with proper grammar and spelling. Refer to the tables (by label and number) throughout the summary. Use the proper statistical terms and symbols in the summary.

• Discuss the point estimate and how it is determined.

• Discuss the relationship between the confidence level and the critical value.

• Discuss the error and how the confidence interval is created. Do not describe the arithmetic steps.

• Interpret each confidence interval using the concepts presented in the textbook.

• Compare the 2 different confidence intervals, noting the differences in the critical values and errors.

• The population for the data in this assignment is the numbers from 1 to 75. The population mean is µ=38 and the population standard deviation is =21.6. (How is this determined?) Compare the sample mean and standard deviation to those of the population. Does either one or both of the confidence intervals contain the population mean?

## Format Requirements

• The introduction and summary should be written in paragraphs that are typed and double-spaced, with 1-inch margins and a readable font type and font size (such as size 12, Times New Roman).

• The introduction should be at least 50 words.

• The summary should be at least 150 words.

• The introduction and summary should be college-level writing with proper grammar and spelling. With the exception of the interpretation of the confidence interval, do not use first or second person (I, you, etc.).

• Throughout the introduction, tables, and summary, proper statistical symbols and terms should be used.

• The title page, introduction, tables, and summary should be a single document (.doc, .docx, or .rtf) which is submitted to the proper Dropbox in Falcon Online by the due date.

• Organize the document as follows: title page, introduction, results and tables, summary; the introduction, results, tables, and summary should be merged into a continuous report and not be placed onto individual pages; do not allow tables to be split across 2 pages