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Hello my name is Beth Dixon and this is a video series on simple random samples
I want to give a special thank you to Vicki Borlaug for the use of her power points for this video
I will cover the following three topics in this video series
finding a random number
take a random sample of one member from a finite population using the TI-84
take a simple random sample of size n from a finite population using the TI-84
and I will break down this series
of videos into multiple videos if I run over time
topic one find a random number
there are many ways we can pick random numbers think about playing a board game or picking a door prize winner
at an event
how do you decide what number to pick
you could use a fair spinner spin the number and the arrow points
to the number
why does it why do we have to use the word for fair
otherwise it would not be a random number
you can roll of fair die
again we use the word fair it would not be a random number
if it landed say on the number three more often than any other number
or we can pick a numbered ball from a container like in the lottery
here at Walter state we use the TI-84 calculator and the random number generator command
the command will look like this
random integer randINT is the command and 1 to 6 tells the calculator to pick
a number between one and six including one in six or inclusive
I have to consider this some of the people watching this video may have a brand new
calculator or one that has never used this command
so before we use that random number generator on the calculator we will need to seed it
we will only need to seed the random number generator once it will not need to be done again unless we reset the whole calculator
if you did this in class you will not need to do this again
here are the steps to seed the random number generator
put and any number make up your own number don't use the one on the screen
we should all seed our calculators differently
then you'll press the store key to get the arrow
press the math key
go over to PRB which stands for probability and select
Rand which stands for random
press enter and your number will reappear
and that's all there is to it we have seeded the calculator we only need to do that -- this this
one time unless we hit the reset button on the calculator you will not need to do this again
now let's look at how it looks on an actual calculator
so using the actual calculator to do this let's quickly go through this put in any number and again you want to type in just in any number
and the length doesn't even matter
but you don't want a very short number
then press the store key which is right down here next to the four gives you the arrow
then press the math key here
over to the probability using the over arrow
and once you get to probability the random is number one so you can press one or enter and that will give
you to rand press enter gives you the same number back and we're done
now we will cover the steps on the calculator to get a random number between one and six on the calculator
press the math key
go to probability
and select random integer
type in one comma six and the end parentheses or close parentheses )
your screen will look
like the one on the right
press enter and a random number between one in six will appear
you will not necessarily get the three
it's a random number
so you will get something different or three
continuing to press enter
will give you more random numbers
between one and six try it and see what you get
let's look at how it looks on the real calculator
ok let's begin and press the math key
then over to the probability key
then down to random integer we could have also just pressed the five key either one
then we get random integer and we type in a one
comma six
close the parentheses
then press enter
and we get a random number notice that I did not get the same random integer that Mrs.
Borlaug did in her PowerPoint that's OK it is choosing a random number
between one and six actually the first time I taped this I did get the same number she did it
just is a random pick then if I hit enter again I will get another number its like a rolling
die again and again
and again I can continue to do this notice I get two 4's
if I didn't and I role again and I role again and I can just continue
to do that
so what we have just completed if we do one time it's like a rolling the dice once
if we do it repeated times it's like rolling and die over and over and over again repeatedly
now let's look a little bit more at the command the calculator command to get are random
number between one and six is random integer one to six -- one comma six
the calculator command to get a random number
between one and 20
is random integer 1 comma 20
what would the calculator command to get a random number
between one and 75 be
it would be random integer 1 comma 75
what would the calculator command to get a random number between one and 14 be
random integer 1 comma 14
the calculator command to get a random number between one and 22
random integer 1 comma 22
the calculator command together random number between one and 63
random well I am going to leave that for you....
nah...I'll just tell you it'll be the random integer 1 comma 63
and I'm pretty sure that this is going to hit the 10 minute mark so
I'm going to end the first video here and we'll start the second video here as well thank you for listening and watching and I hope this was
helpful on learning to use the calculator generate random numbers
please watched the second video
where we'll conclude in this an actual sampling
from a finite population
All spelling errors are mine...please no comments or laughter-----Beth Dixon