Math 1530: Project 3
Math & Computer Science Building

Data & Statistics Projects

Project 3  

Minitab and Inferences with Your Data

Group Expectations

Meetings:  Each group should meet at least twelve hours before each report is due.  For this project, the group may want to have one additional short meeting at the very beginning to complete the preliminary planning, where the group chooses the three hypotheses to be proven (see below).

1st Draft:  Before meetings and at least 48 hours before the report's due date on the syllabus, each group member should post a draft version of their part of the report in their D2L group discussions.  Before meetings and at least 36 to 24 hours before each report is due, the group leader should post to the group project's dropbox a draft of the entire report.  All group members will be responsible for grading the dropbox-posted project with the rubric and editing the project whenever the rubric is not met.  The group should go through the entire report, discussing each part and matching each part to the rubric.  Each group member is responsible for the accuracy of all calculations; the clarity, completeness, and accuracy of the answers to all questions; and the overall report presentation, style, and quality.  If any group member feels a part of the report does not meet rubric specifications, is incorrect, or is lacking in any way, that part of the report should be discussed and revised by the group at this group meeting.

Evaluate your peers by submitting one peer review for each member of your group.  Individual grades will greatly depend on turning in your own evaluations by the due date and in the evaluations of you by fellow group members.

The group leader will immediately (within 2 to 3 days of each previous project or pre-project being due) assign all parts to the various group members, keeping the Wrapping It Up part for himself or herself and splitting the remaining parts as equally as possible based on the point distribution in the rubric and the part divisions already assigned in the project description.  The group leader is responsible for ensuring group members post their respective assigned parts of the project at least two days prior to the project due date - or even earlier if the leader specifies an earlier time when assigning parts, at the leader's discretion.  If a group member is late, the leader will reassign that member's part to active group members and will let the instructor know immediately.

Other members will be responsible for completing all assigned parts at least two days prior, or even earlier, if specified, and posting those parts to the group discussion board.  If the group leader has not assigned roles for the project within two to three days of the previous project or pre-project being due, then the group contact the instructor know immediately.  Any student who does not understand completely his or her assigned part should immediately ask for clarity and help from group members. Any member turning in his or her part late may receive a zero for the current project if this part was assigned and completed by another member because of the lateness. 

Report Expectations

In formal, professional reporting style, the full report for Project 1 needs to be written to include everything in the parts below, although the questions themselves should not be included. This report should read as if the reader has no knowledge of these questions nor any knowledge that the questions have prompted the writing of the report. The entire report should be in complete sentences and full paragraphs with the exception of tables, charts, graphs, equations, and lists of statistics. Everything from formatting to grammar to style should be as professional as possible.

To be successful with this project, students should:

  1. Use both Minitab and the calculator for each part.  
  2. Only save the project in Minitab when finished with the entire project:  Parts 1-6.  
  3. When rounding, give at least three significant digits for final answers and at least four significant digits for answers that will be used in future calculations.
  4. Present a neat, organized and clearly communicated project document.  Students have the latitude to present work on this project in any professional manner.
  5. Don't assume what the question is asking unless certain. Looking up items can dramatically improve the group grade.  Please feel free to ask questions in the Data & Statistics Projects discussion, especially when clarity is needed on what is being asked.
  6. Students who don't complete and post assignments to group discussions at least two days prior to the syllabus due date for the report will receive between 0% to 50% of the group project grade.
  7. Reports should be professionally written and completely without reference to this set of instructions or questions. Even though all questions and parts listed here should be addressed using the same or similar terminology within the report, preferably in order, the reader of the report should not be aware that the report was guided by a set of questions or instructions.

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Preliminary Planning

Without looking at the data, your group should sit down and make some guesses about what the data is like.  Choose two of your quantitative variables and one of your categorical variables. 

For the two quantitative variables, make some hypothesis (guess) as to what the population mean (the mean of everyone in your population, not just the sample) is less than, more than, or not equal to.  You just have to choose one of those three options for each variable.  For example, I might guess that the mean rating of the Harry Potter movie would be at least 5.  My guess is the alternative hypothesis.  Ha: mu > 5.  (We'll learn about hypothesis testing in 9.1, 9.2 and 9.3.)  My other variable guess might be that the mean rating of the Harry Potter book would be at least 6, in which case Ha: mu> 6.

For the categorical variable, choose one of the categories (perhaps the most popular or your favorite category) and make a guess as to the proportion of your population in that category, whether the proportion is less than, greater than, or not equal to a certain value.  Keep in mind that proportions are always numbers between 0 and 1.  For example, I might guess that the proportion of the population choosing Harry Potter as their favorite character would be less than 0.30:  Ha: p < 0.3.

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Minitab:  Inferential Statistics

Opening Minitab and start with the data you collected from Project 1.  You can do this by using your Minitab file from Project 2, but erase all of the session window.

In the Minitab session window, type the following in the session window:

                Your Group Name
                List of Group Members' Names
                MATH 1530 Elements of Statistics
                Project #3: Minitab

                Due Date:  (actually type the due date)
  

1 - Select Stat Basic Statistics 1t 1-Sample t Click in the box titled Samples in columnsDouble-click your first chosen quantitative variable and click Options.   At the Confidence Level, type 95.  Be sure that the alternative is not equal to for the confidence intervals. Click OK and OK.  The confidence interval will be displayed in the session window.

2 - Select Stat Basic Statistics 1t 1-Sample t Click in the box titled Samples in columnsErase your previous choice and double-click your second chosen quantitative variable and click Options.   At the Confidence Level, type 95. Be sure that the alternative is not equal to for the confidence intervals. Click OK and OK.  The confidence interval will be displayed in the session window.

3 - Select Stat Basic Statistics 1 Proportion Click in the box titled Summarized Data For number of events, type in the number of times in your sample that this particular category appeared - the category you chose in preliminary planning to hypothesize on.   For number of trials, type in your sample size.  Under Options, at the Confidence Level, type 95. Check the box to use the interval based on a normal distribution.  Be sure that the alternative is not equal to for the confidence intervals. Click OK and OK.  The confidence interval will be displayed in the session window.

4 - Select Stat Basic Statistics1t 1-Sample t Click in the box titled Samples in columns Erase your previous choice and double-click your first chosen quantitative variable and click Options Check the Perform Hypothesis Test box Use the value you chose in preliminary planning for the Hypothesized Mean.  (In older versions of Minitab, the hypothesized mean is called the test mean.  There also may not be a box to check in older versions, but as long as you've entered the test mean Minitab will compute the hypothesis test.)  Click Option and indicate a 95 confidence level, denoting that we are to have 95% confidence in the alterOptionsnative hypothesis if accepted, and choose the appropriate alternative hypothesis symbol.  Click OK and OK The test statistic and p-value will be displayed in the session window.

5 - Select Stat Basic Statistics1t 1-Sample t Click in the box titled Samples in columns Erase your previous choice and double-click your second chosen quantitative variable and click Options Check the Perform Hypothesis Test box Use the value you chose in preliminary planning for the Hypothesized Mean Click Option and indicate a 95 confidence level, denoting that we are to have 95% confidence in the alternative hypothesis if accepted, and choose the appropriate alternative hypothesis symbol.  Click OK and OK The test statistic and p-value will be displayed in the session window.

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6 - Select Stat Basic Statistics1Proportion Click in the box titled Summarized Data For number of events, type in the number of times in your sample that this particular category appeared - the category you chose in preliminary planning to hypothesize on.   For number of trials, type in your sample size.   Check the Perform Hypothesis Test box Use the value you chose in preliminary planning for the Hypothesized Proportion Under Options, at the Confidence Level, type 95. Check the box to use the test based on a normal distribution, and choose the appropriate alternative hypothesis symbol.  Check the box that says Use test and interval based on normal distribution.  Click OK and OK The test statistic and p-value will be displayed in the session window.

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The Report

1 - Copy and paste the first confidence interval results from Minitab into the report. Compute the confidence interval using your calculator and the data option and report the calculator results including all of the digits that the calculator displays.  Compare Minitab and calculator results, explaining any discrepancies.  Interpret what these results for the confidence interval mean.  Explain if the confidence interval supports or contradicts your original hypothesis about this variable.

2 - Copy and paste the second confidence interval results from Minitab into the report. Compute the confidence interval using your calculator and the data option and report the calculator results including all of the digits that the calculator displays.  Compare Minitab and calculator results, explaining any discrepancies.  Interpret what these results for the confidence interval mean.  Explain if the confidence interval supports or contradicts your original hypothesis about this variable.

3 - Copy and paste the third confidence interval results from Minitab into the report. Compute the confidence interval using your calculator and the data and report the calculator results including all of the digits that the calculator displays.  Compare Minitab and calculator results, explaining any discrepancies.  Interpret what these results for the confidence interval mean.  Explain if the confidence interval supports or contradicts your original hypothesis about this variable.

4 - Copy and paste the first hypothesis test results from Minitab into the report. Compute the hypothesis test using your calculator and the data option and report the calculator results including all of the digits that the calculator displays for the t- and p-values.  Compare Minitab and calculator results, explaining any discrepancies. 

Do the full, five step process for the hypothesis test.  1) Discuss assumptions and how or if they are met.  2)  State null and alternative hypotheses.  3 and 4)  Report t- and p-values.  Decide whether to reject the null or not and explain why.  5) Interpret what these results for the mean in the context of the variable and the population.

Explain if the hypothesis test supports or contradicts your original hypothesis about this variable.  Is this consistent with the confidence interval for this variable (i.e., are the confidence interval results and hypothesis test results consistent with each other)?  Given your alternative hypothesis, would you expect the confidence interval results and hypothesis test results to always be consistent?

5 - Copy and paste the second hypothesis test results from Minitab into the report. Compute the hypothesis test using your calculator and the data option and report the calculator results including all of the digits that the calculator displays for the t- and p-values.  Compare Minitab and calculator results, explaining any discrepancies. 

Do the full, five step process for the hypothesis test.  1) Discuss assumptions and how or if they are met.  2)  State null and alternative hypotheses.  3 and 4)  Report t- and p-values.  Decide whether to reject the null or not and explain why.  5) Interpret what these results for the mean in the context of the variable and the population.

Explain if the hypothesis test supports or contradicts your original hypothesis about this variable.  Is this consistent with the confidence interval for this variable (i.e., are the confidence interval results and hypothesis test results consistent with each other)?  Given your alternative hypothesis, would you expect the confidence interval results and hypothesis test results to always be consistent?

6 - Copy and paste the third hypothesis test results from Minitab into the report. Compute the hypothesis test using your calculator and report the calculator results including all of the digits that the calculator displays for the z-scores and p-values.  Compare Minitab and calculator results, explaining any discrepancies. 

Do the full, five step process for the hypothesis test.  1) Discuss assumptions and how or if they are met.  2)  State null and alternative hypotheses.  3 and 4)  Report z- and p-values.  Decide whether to reject the null or not and explain why.  5) Interpret what these results for the mean in the context of the variable and the population.

Explain if the hypothesis test supports or contradicts your original hypothesis about this variable.  Is this consistent with the confidence interval for this variable (i.e., are the confidence interval results and hypothesis test results consistent with each other)?  Given your alternative hypothesis, would you expect the confidence interval results and hypothesis test results to always be consistent?

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Wrapping It Up

Have a paragraph at the end detailing what exactly each group member did to contribute to the entire group effort.

You will want the document to have a title page with a title for the paper, Math 1530, the date, the name of the group, and a list of the group members. 

Save your MS Word document as Project3_GroupName.doc or Project3_GroupName.docx

Load the files to the dropboxes.  Open the files straight from the dropboxes so that you can grade the files that are in the dropboxes.  Print the group project rubric and grade your report, correcting anything in the report that fails to fully satisfy the rubric.

After grading and correcting your report, load the report to D2L's Project 3 Report dropbox.  Every single group member needs to reopen the MS Word report straight from the dropbox to make sure that all parts are completely answered and that this report is the latest, best edited version.  Every single group member will be held responsible for making sure that the report is accurate, complete, and of the highest quality by grading the report with the rubric. 

Evaluate your peers by submitting one peer review for each member of your group.  Individual grades will greatly depend on turning in your own evaluations by the due date and in the evaluations of you by fellow group members as well as evidence in what you did in that last report paragraph and in the discussion forum.

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