Week 2: Correlation and Regression - iLab

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iLab

Connect to the iLab here.

Submit your assignment to the Dropbox located on the silver tab at the top of this page.

(See Syllabus Due Dates for Assignments & Exams for due dates.)

 

i L A B  O V E R V I E W

Open the Week 2 Lab Document to complete the lab for this week. All the directions are included in the document.

The document includes places where you need to input the answers.

Use the Connect to the iLab here link above to access the Minitab application

Fill in the document, save it with your name in the title, and submit the document through the Dropbox.

Lab Week 2 InstructionsPart 1 Opening Minitab

Open MS Internet Explorer

Navigate to this URL

http://lab.devry.edu

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Open MiniTab

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MiniTab Screen

Part 2 Importing Minitab Files from eCollege

With Minitab open, navigate to the Doc Sharing to copy the Minitab files that are to be used for the iLab assignment.

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Select the " Online Course Resources " link in Doc Sharing.

Download the file: MATH221_W2 LabData Minitab.MPJMATH221 Week 2 LabData Minitab

 Online course resources

Upload Document| Download Documents

File Name/Description Owner Date/Time* Size Share Downloads Edit Delete

MATH221_W2 LabData Minitab.MPJMATH221 Week 2 LabData Minitab

DVU * 3/29/2011 10:29:29 AM 13K Entire Class 7

MATH221_W2 LabData Excel.xlsxMATH221 Week 2 LabData Excel

DVU * 3/29/2011 10:28:56 AM 10K Entire Class 0

Save to C:\ Drive Temp folder( you can create a folder in the c:\ drive and name it as temp )

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Return to Minitab and click [ File ] and then [Open Project]Navigate to the V: Drive ( which is the same as your local computer's C: Drive )

Allow Citrix to access your document.

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Copy your Minitab worksheet from your C:\temp location.

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Return to the My Documents location in your iLab account and paste the Minitab worksheet there.

Click the file and open it in Minitab.

Part 3 Using Minitab

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Complete the iLab for Week 2 .

Creating Graphs

1. Create a Pie Chart for the variable Car – Pull up Graph > Pie Chart and click in the categories variables box so that the list of variables will show up on the left. Now double click on the variable name ‘Car” in the box at the left of the window. Include a title by clicking on the “Labels…” button and typing it in the correct text area (put your name in as the title) and click OK. Click OK again to create graph. Click on the graph and use Ctrl+C to copy and come back here, click below this question and use Ctrl+V to paste it in this Word document.

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2. Create a histogram for the variable Height – Pull up Graph > Histograms and choose “Simple”. Then set the graph variable to “height”. Include a title by clicking on the “Labels…” button and typing it in the correct text area (put your name in as the title) and click OK. Copy and paste the graph here.

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Calculating Descriptive Statistics

3. Calculate descriptive statistics for the variable Height by Gender – Pull up Stat > Basic Statistics > Display Descriptive Statistics and set Variables: to Height. Check By variable: and enter Gender into this text box. Click OK. Type the mean and the standard deviation for both males and females in the space below this question.

Mean Standard deviationFemalesMales

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Select File > Save Worksheet As to save the data set. You must either keep a copy of this data or download it again off the web site for future labs.

Group Discussion for Week 2 (1) Differentiate between correlation and regression.(2) When does an r value exhibit weak correlation?(3) What is a scatter plot? Why is it useful in statistics?(4) What is non - linear regression?(5) Explain how you can use MS Excel to obtain a " line of best fit ? "(6) What is meant by non - parametric statistics?(7) Find the value of x such that y will be equal to 85,000 in the following equation:

y = -200x + 5000 (8) What is meant by multiple correlation? Give an example of a scenario that exhibits multiple

correlation.(9) Why is " y " often called the response variable? Give an example of a response variable.(10) Why is the correlation coefficient ( r value ) often express as a square?

_____________________________________________________________________________________

Group Discussion for Week 2 (1) Differentiate between correlation and regression.

[ Answer: Correlation is a relationship between 2 variables, the data can be represented by ordered pairs and regression line also called “best fit” is the line for which the sum of the squares of the residuals is a minimum. [ group name ] Guadalupe Dominguez & Anthony Jara

(2) When does an r value exhibit weak correlation?[ Answer: The value of r exhibits weak correlation when r is close to 0. ][ Huggin’ Bear ]

(3) What is a scatter plot? Why is it useful in statistics?[ Answer:

The graph of ordered pairs(x,y) is called a scatter plot. A scatter plot can be used to determine whether a linear(straight line) correlation exists between two variables. In a scatter plot, the ordered pairs are graphed as points in a coordinate plane. The independent(explanatory) variable x is measured by the horizontal axis, and the dependent(response) variable y is measured by the vertical axis. It is useful in statistics because it can show us regression analysis.

][ Phone searchers] Luis an Alba

(4) What is non - linear regression?[ Answer: A non- linear regression is a way of regression analysis in which observational data are modeled by a function which is a non-linear combination of the model parameters that also depends one or more independent values.

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][ group name ]

(5) Explain how you can use MS Excel to obtain a " line of best fit ? "[ Answer:We can use the LINEST() function to determine the slope an intercept of the line of best fit. ][ group name Spartan_LP ]

(6) What is meant by non - parametric statistics?[ Answer: Non-Parametric Statistics are those that do not rely on data belonging to any particular distribution or that do not assume that the structure of a model is fixed

][ group name ] Phone Searchers Luis and Alba

(7) Find the value of x such that y will be equal to 85,000 in the following equation:y = -200x + 5000

[ Answer:y=-200x+500085000=-200x+5000 -5000 from both sides80000=-200x Divide both sides by 20040 = -xErgo x=-40

][ group name: Schrodinger’s cat / 0= ] Perry Gunderman, Melissa Carter

(8) What is meant by multiple correlation? Give an example of a scenario that exhibits multiple correlation.[ Answer: A correlation is a relationship between variables. Now multiple correlations are

relationship between multiple variables. Simple as that! An example of multiple correlation is let’s look at y=-200x+5000. A multiple correlation would be y=-200x+(that u thing) sigma pie or something of that nature xD.

][ Team different ethnicity ]

(9) Why is " y " often called the response variable? Give an example of a response variable.[ Answer:Y is the response variable because it the explanation of why we have the X variable.

][ group name Team A]

(10) Why is the correlation coefficient ( r value ) often express as a square?[ Answer: The correlation coefficient (r value) is often expressed as a square to sneakily disguise a negative value.

][ group name Team A]

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