Minitab Introduction by 4xXk1Q


									BIOL/STAT 335 Introduction to Minitab and Instructions for the first Minitab Lab Assignment

    1.   Logging on and getting Minitab working. You may use any computer on the Loyola Network, including the computer in Damen
         342. First, you will need to log on using your Loyola logon id and password. Next, open up the Minitab software package (follow
         “Start  Programs  Loyola Software  Statistics Applications  Minitab”). It is important that you get familiar with working
         with Minitab and especially with interpreting the output and subsequently drawing the relevant correct conclusion. While in Minitab,
         at any point you can obtain online help by clicking on the “Help” button and going down to “Search for help on” choice.
    2.   Next, let’s get familiar with Minitab by working through three basic problems.

    (a) Importing data from the CD provided with your textbook. Let’s work with the serum creatine phosphokinase data of Exercise
        2.50 on page 49 in the text to illustrate importing data from the textbook CD. To do this, open up the Minitab software package
        (follow “Start  Programs  Loyola Software  Statistics Applications  Minitab”). Open the file on your Samuels/Witmer CD
        (within Minitab click on File  Open Worksheet. Do NOT click File  Open Project), making sure that “File of type” has “All
        (*.*)” highlighted, clicking on the file “Serum-ck.mtp,” and finally clicking on the “Open” and “OK” buttons. The data values
        should appear in the column “C1.”
        An alternative way of doing this is to use the MS browser Internet Explorer to go to our class web page and find the file after
        clicking on “Data Files”. The Mozilla browser Firefox does not seem to work this way.
        (You can get a histogram of the data by clicking on “Graph” then “Histogram,” then typing “C1” under “X” (or double clicking on
        “C1” while the cursor is under “X”), and hitting the “OK” button. Summary statistics can be obtained for these data by clicking on
        “Stat,” then “Basic Statistics,” then “Display Descriptive Statistics,” and entering “C1” under “Variables.” Please do not print out
        the graphs and output for this exercise (you are charged for printing}, rather, just use the results you see to answer the first question
        on the accompanying Assignment sheet. Once you’re finished, you can close all the graphs and get a fresh worksheet by highlighting
        the first column and clicking “Edit” and “Delete Cells.” You can clear the Session window by highlighting and hitting the Backspace

    (b) Typing in your own data. For small data sets, typing in the data is not a problem. For example, an ecologist counts the number of
        moths caught in ten different traps and obtains the data: 2400, 6500, 320, 2700, 80, 230, 490, 13000, 1200, 300.
             1. Type in these data into column “C1” (you could give the column a name like “Counts” if you’d like) and obtain descriptive
                statistics and plots as above.
             2. Before proceeding further, please answer the first part of the second question on the Lab01 assignment.
             3. Once this is completed, our goal is to transform the data using the natural logarithm transformation (called “loge” in
                Minitab). Click on “Calc,” then “Calculator,” enter “c2” after “Store results in variable,” and type “loge(c1)” under
                “Expression,” then hit “OK.” The natural log’s of the original counts will then appear in the second column.
             4. Now finish the second exercise, and, once finished, clear the worksheet as above.

    (c) Having the computer generate random data to perform a simulation study. Now let’s generate 200 samples of size n from an
        exponential distribution with mean = 3.0. With the student version of Minitab, please be aware that you are limited to 5000 entries in
        your worksheet. I
             1. To give you and idea of the corresponding probability histogram (“the population”), type the integers 0, 1, 2, through 20
                into the first column.
             2. Obtain the probabilities in the second column by clicking “Calc,” “Probability Distributions,” “Exponential.” In the
                displayed table make sure that “probability density” is checked. Enter “3.0” after “Mean,” then “c1” after “Input column,”
                then “c2” after “Optional storage,” and hit “OK.”
             3. Then graph these probabilities by clicking “Graph,” “Plot,” “Y” is “c2” and “X” is “c1,” then “OK.” Note that our
                population follows an exponential curve and is very skewed to the right.
             4. Now clear these values, and generate 200 samples of size n = 4 from this population by clicking “Calc,” “Random Data,”
                “Exponential,” after “Generate” type “200” to get 200 rows of data (each one is a sample), after “Store in Column(s),” type
                “c1-c4,” type “3.0” after “Mean,” then hit “OK.”
             5. Let’s form the sample average of each of these samples of four integers by clicking “Calc,” “Row Statistics,” clicking next
                to “Mean,” “Input variable(s)” are “c1-c4,” and “Store results in” “c5”, then hit “OK.”
             6. Now answer the first part of question 3 of the Lab01 assignment.
             7. Once finished, repeat the above process, but store the random data in the columns “c1-c9” and put the sample means into
                “c10,” and answer the second part of question 3 of the Lab01 assignment.
             8. Now repeat the above process, but store the random data in the columns “c1-c16” and put the sample means into “c17,” and
                answer the third part of question 3 of the Lab01 assignment.
             9. Finally, to answer the final part of the third question, repeat the above process for random data stored in columns “c1-c24”
                and the sample means stored in column “c25.”

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