Download Intro to Minitab

Intro to Minitab
Wyatt Toolson
5/23/05
When you first open up Minitab, there should be two windows inside it, called Session
and Worksheet. The Session window is the one that first lists the date and time you
opened Minitab and says “Welcome to Minitab, press F1 for help.” The Worksheet
window is the spreadsheet. This is where the actual data will go. Depending on how you
try to find your results, they might appear in the Session window, the Worksheet window,
or a graph that you create. If you do not see both the Session and Worksheet windows,
go to Window and click on Tile.
To open a Minitab worksheet (the data on the CD-ROM), insert the CD-ROM, open
Minitab, and go to:
File -> Open Worksheet -> My Computer -> Devore6e(E:) -> Manual Install ->
Datasets -> Minitab.
Then select the chapter of the problem you are asked to do. The worksheets are named
ex** - ##, where ** is the chapter you have selected and ## is the exercise number.
Double click on the appropriate file for the problem you’re going to do. This will add the
data from the book into a Minitab worksheet.
After adding the data, click on the Session window. Then click on Editor and make sure
that the Enable Commands option is checked. If it is not, click on it once. Once
commands are enabled, you should see a MTB> appear in the Session window. You can
now type in commands into the Session window for Minitab to execute.
The easiest way to compile your results is a Word document. Minitab data, charts,
graphs, and outputs can be copied and pasted into Word for a clear and legible solution.
Don’t forget to type your name, section, homework number, and date in the upper righthand corner.
EX01-17
To determine frequencies and relative frequencies, go to
Stat -> Tables -> Tally Individual Variables.
Double click on C1 to list it in the Variables box and click ok. You should see a list
appear in the session window. This is the frequency of each value.
Copy this chart and paste it in the worksheet, with the column headers in the second row
of gray boxes, in C2 using spaces as delimiters. Then in the session window, type “let
c4=c3/60” without the quotes. This produces values of the relative frequencies of each
value.
To find the proportion of batches with at most five nonconforming transducers, highlight
the appropriate values from the relative frequencies and copy and paste them into C5.
Then type in the session window “let c6=sum(c5)” without the quotes. The value found
in C6 will be the percentage of batches that have 5 or fewer nonconforming transducers.
To find the proportion with fewer than five or at least five, follow the same steps as
above, but change what values you copy and paste.
To draw a histogram, go to
Graph -> Histogram.
Select Simple and click ok. Double click on C1 to put it in the Graph Variables box and
click ok. Note, it is likely that three Run-Time Error messages will pop up. Don’t worry
about this and just click continue when each one appears. This will probably occur for
every graph you make on any subsequent assignment as well. This plots the frequency of
each value for each value. To change it to relative frequency, double click on the
Frequency axis. Click the Type tab and select Percent. Click ok. Now the histogram
shows the relative frequency of each value.
EX01-21
Exercise 21 is very similar to Exercise 17. The same general steps, with a few
modifications, can be followed to determine the desired results.
To determine frequency, follow the steps outlined above. However, since we are
beginning with two columns, we must specify which column we want to tally first. After
getting to the tally window, first double click on “C1 y:” and click ok. This gives us a
tally for y. Then follow the same steps as above to produce a histogram of relative
frequencies for y and find the desired proportions.
For z, go back to the tally window. This time, instead of double clicking on y, double
click on z and click ok. Now we have a tally for z. Again, follow the steps from above to
produce a histogram and find the proportions asked for in the problem statement.
EX01-33
To find the mean of C1, type “let c2=mean(c1)” in the session window. The value
produced in C2 is the mean. Similarly, if you type “let c3=median(c1)”, C3 shows the
value of the median of C1.
Change the value of 244 to 204 by clicking on 244 and typing 204. To find the new
mean and median, repeat the code above.
To easily see which is the largest and smallest value of a list of numbers, type “let
c4=sort(c1)”. This orders the data from smallest to largest, which should let you quickly
delete the largest and smallest values, and then calculate a trimmed mean by the same
steps as above.
Alternatively, one can go to
Stat-> Basic Statistics -> Display Descriptive Statistics.
Then selecting the appropriate column, here C1, and clicking ok, we get a list that
includes the mean, standard deviation, minimum value, median, maximum, and first and
third quartiles. Then modify the data and find the new means and medians as requested.
EX01-34
Following the steps from above, you should be able to quickly calculate the values for the
mean, median, and trimmed mean.
EX01-47
This follows the same procedure as EX01-33, except we now care about the standard
deviation value.
EX01-50
The easiest way to do this problem is to find the standard deviation, the mean, and then
twice the standard deviation from the mean. By now, you know how to quickly call up
the statistics to give you the mean and standard deviation. Thus, going two standard
deviations away from the mean gives you the maximum award that the woman should be
eligible for.
EX01-59
Call up the descriptive statistics for both ED and Non. This gives you the medians and
the fourths for the two samples. To see a boxplot go to
Graph -> Boxplot.
In this situation, since we want a comparative boxplot, select Multiple Y’s, Simple. Click
ok. Double click on both ED and Non to put them in the Graph Variables box and click
ok. A boxplot should appear. Notice that the outliers are denoted as stars on the boxplot.
EX01-75
Again, for a comparative boxplot, go to
Graph-> Boxplot
and pick Multiple Y’s, Simple. Double click on all three types and click ok. A boxplot
with all three samples should appear.
For a comparative dotplot, go to
Graph -> Dotplot
and choose Multiple Y’s, Simple. Double click on each type and click ok. A graph with
three plots should appear, with one for each different type.