M17 Basic Descriptive Stats Video Lecture | Mintab Tutorials for Beginners - Data & Analytics

welcome to Minitab 17 where we're going
to learn a little bit about Minitab and
we're going to use it to calculate some
basic descriptive statistics so first
let me introduce you to Minitab you've
got a menu bar up here on the top you
have what's called a session window so
as we do things in Minitab they're going
to show up in the session window but you
can also type in the session window just
like it was a word processor except you
don't get a lot of cool fonts but I can
say hey I am typing in the session
window so if you ever need to make notes
if you're doing homework and you want to
put things in the session window you can
write your own notes you don't just have
to have the results of Minitab things
this bottom section is called the
worksheet and it looks kind of like an
Excel spreadsheet but it's a little bit
different in that everything has to be
in columns so you'll see here I have a
column C one called F height and I've
got the heights of women in centimeters
that would be huge if they were in
inches listed in the same column I can't
work in rows in Minitab I have to work
in columns so this first column is the
heights of women the next column is the
heights of men again in centimeters over
here I've got some diastolic and
systolic blood pressures for both men
and women and I've recorded their
heights in this column c6 gender you'll
notice the c6 has a tee after it that's
because it is a text column once you put
text in Minitab says it's a text column
and it won't let you do things like find
the mean of a text column because that
doesn't make any sense all right that's
the three things your menu your session
window and your worksheet that you might
want to know about let's start to use
Minitab to actually do something let's
calculate some basic descriptive
statistics so for example let's find the
mean height the standard deviation of
the heights of these females so I'm
going to go up here to my menu and then
one I'm going to use is stat most of the
statistical things we're going to do are
going to be in our stat menu most of the
graphical things we're going to do if
graphical is a word and I think it is
are going to be in the graph menu I'm
going to go to stat and what I want to
do is go then to basic statistics and
I'm just moving my mouse there and
another menu opens up to the side of it
and I wanted to display descriptive
statistics I'm looking for mean standard
deviation
the basic descriptive statistics so I'm
going to go to display descriptive
statistics it even tells me if I leave
my mouse over it what that's going to do
and click on it now Minitab opens what's
called a dialog box and it says
variables it's saying hey Eric what
variable do you want to find the
statistics on well I want to find it on
F height so I'm going to go over here to
F height put my mouse on it then I have
two choices I can either click that and
then click select or I could have just
double clicked F height and it would put
it in the variables box all right now at
this point I could choose which
statistics I wanted but I'm just going
to say okay and let Minitab do its
default statistics for the moment so I'm
going to click on OK
and you'll see Minitab here in the
session window it gives me the basic
statistics of f height n is how many
there are there's 35 and star there's no
missing elements there's no lines I
skipped the mean height is 164 point
three five centimeters the standard
deviation is seven point zero nine
centimeters notice this one is not the
standard deviation that's called the
standard error of the mean I didn't want
that but I might have wanted the mean in
the standard deviation I've also got the
minimum in the maximum I've got both
quartiles in the median
I can tell Minitab not to give me all of
these I can tell Minitab to give me more
let's do it with men's heights
let's only get the mean the standard
deviation and the median let's turn off
some of the other ones and I'll show you
how I'm going to go to stat basic
statistics display descriptive
statistics this time I don't want F
height I'm going to double click M
height and then before I click OK I'm
going to hit statistics and you'll see
it's got checkmarks next to all the
statistics that are being used now I
don't want the standard error of the
mean so I'm going to uncheck it I don't
want the minimum in the maximum or how
many and what the sample size is and I
don't want the first quartile in the
third quartile I only want the mean the
standard deviation in the median maybe I
want the mode so I click on the mode and
now I'll get the mode as well then I say
ok and okay and now I get the height for
men the mean height is 175 point eight
seven inches with a standard deviation
of six point one six I'm sorry inches
not inches centimeters centimeters
minitab of course has no idea what the
units are I have to know what the units
are a median of one hundred and seventy
six point one zero centimeters and
there's a star here meaning that there's
no mode if there were a mode and four
mode would tell me how many times that
mode appeared so there's no mode at all
nothing appeared more than once
excellent now maybe though I wanted to
look at the female height and the men
height side-by-side and in Minitab I
don't have to just do one at a time let
me show you what I mean I can go to stat
basic statistics display descriptive
statistics and I could double click F
height and I could double click M height
and I could put both of them in and now
say okay and you'll see it calculates
them one right on top the other there's
the female height and I can easily
compare it to the male height in
centimeters
I can easily compare the standard
deviations because there's one right on
top of the other same thing with the
medians and obviously neither one had a
mode so we're good there now there's
another way I could do it let's look at
our blood pressure see how I have
diastolic and systolic blood pressures
well I want to look at those
so let's first just find the mean
standard deviation median and mode of
the diastolic and systolic blood
pressures so I'm going to say stat basic
statistics and I'm going to display
descriptive statistics and this time I
want to do diastolic and systolic and
I'm going to say ok and Minitab will
tell me the mean diastolic pressure is
80 point zero one two that would of
course be in millimeters of mercury the
systolic 120 point two nine here's the
standard deviations of each group
there's the medians of each group
neither one has a mode but I want to
know males versus females I want to know
I want to compare the diastolic blood
pressures of men and the diastolic blood
pressures of women I want to compare the
systolic blood pressures of men and the
systolic blood pressures of women so I'm
going to use what's called a by variable
I want Minitab to sort this these
statistics by the gender of the patient
so calculate the mean diastolic blood
pressure for the males and for the
females so I'm going to say stat basic
statistics display descriptive
statistics I'll still do both diastolic
insist I'll
but I want to sort it using what's
called a by variable sort it by gender
so I don't have to have a by variable
but if I go down here and click in this
box by the way you'll notice gender
doesn't show up because you can't
display descriptive statistics on gender
because it's text but when I click in
the by variable box you can sort by a
text variable by a nominative variable
if you're talking about your levels of
data so I'm going to double click on
gender to put that in there and now I'm
going to say okay and watch what happens
diastolic pressure it does females and
males there's the mean diastolic
pressure of females and the mean
diastolic pressure of males same thing
with systolic the means systolic
pressure of females the mean systolic
pressure of males Minitab generally does
things alphabetically since female comes
before male it did the F before the M as
far as diastolic and systolic it's the
same order I put them in
since diastolic I actually double
clicked first it went first so there I
can use Minitab to calculate descriptive
statistics and to sort it by another
column my by variable would have to be
in a column of its own so here I did I
had the gender in a column of its own
whereas with the heights I did not I
couldn't have sorted it by that because
I had the female heights in a separate
column from the male heights here I have
all the blood pressures in the same
column and I sorted by whether or not
they're male or female