Help Me To:
Eligible Content M3.D.3.1.1
Help Me To:
Make a prediction based on data or chance
Did You Know?
In an experiment, the results do not necessarily match the
expected probability. There
is always an element of
chance in any experiment. Also there may be variations
in the results for each person doing the same experiment.
Look at the chart below.
Check What You Know First
Look at the following results of an experiment and answer the questions.
What color was landed on the most times?
On what color would you predict the spinner most likely to land on in future spins?
What color was landed on the least times?
On what color would you predict the spinner least likely to land on in future spins?
If you make a prediction the spinner will land on purple 5 times and blue
1
time in future experiments, could you be wrong?
Key Vocabulary
An event is a something that happens
Probability is the chance that an event will or will not happen
Certain - An event is certain if it will always happen
Impossible - An event is impossible if it will never happen
Likely – An event is likely if it has a good chance of happening
Unlikely - An event is unlikely if it doesn’t have a good chance of happening
Outcome - a possible result of an experiment
Possible outcome - something that has a chance of happening
Equally likely - having the same chance of happening
Predict - to make a reasonable guess about what will happen
Tally Table - a table that uses tally marks to record data
Learn About It Now
It is possible to predict outcomes based on the possibilities
of what might happen.
A prediction is a reasonable guess about what will happen. Based
on the information
in the table above, it is possible to make predictions on future outcomes. An outcome
is a possible result of an experiment.
Systematically keeping track of outcomes, when an event is repeated many times
may
verify the prediction of more/most likely, less/least likely, equally likely
or impossible events.
You can record the results in a tally table like the one above
to help you record data
and organize information. You can make new predictions based on the results
of your
experiment. You can then test the new predictions by repeating the experiment.
In the experiment above, purple was the color landed on the most times. One
might
predict that the color purple would mostly likely be the color landed on in
future spins.
Since blue was landed on the least, one might predict that the color blue would
least
likely be the color landed on in future spins.
One might also conclude that the reason the spinner landed on purple the most
was
that there were more sections of the color purple on the spinner. Another
conclusion
might be that blue was landed on the least because blue had the least number
of sections
on the spinner.
If you made the prediction that the spinner would land on the various sections
the
same amount of times in follow-up experiments, you may find that your prediction
and the results may be close to each other, but they may not be the same. There
is always the element of chance or testing variations that will vary the results
in such
an experiment.
Let’s Try More Practice With This Experiment
Susan fills a bag with 20 marbles. There are 7 blue, 2 green 4 yellow and 7 red marbles.
She pulls a marble from the bag. 
She records the color
on her tally chart. She then put the marble back in the bag and pulls
another marble from the bag.
She pulls a marble from the bag 10 times. Below
is a list of outcomes for the 10 pulls and Susan’s tally chart.
Use Susan’s tally table to answer the questions
What are the possible outcomes?
(Hint – Name all the colors Susan could pull. Separate color words with a comma.)
What color did she pull the least often?
Write down why you think this color was least likely to be pulled.
The second question will be answered later in the lesson.
What color did she pull the most often?
Write down why you think this color was most likely to be pulled.
The second question will be answered later in the lesson.
What colors are equally likely to be pulled?
Write down why you think these colors are equally likely to be pulled.
The second question will be answered later in the lesson.
If she were to pull either a green or yellow, what
color is more likely to be pulled?
Write down why you think this color is more likely to be pulled.
The second question will be answered later in the lesson.
What are her chances of pulling a white marble?
Write down why you answered this question like you did.
The second question will be answered later in the lesson.
If Susan conducts this experiment again, what color do you predict she will pull most often?
If Susan conducts this experiment again, what color do you predict she will pull least often?
If Susan conducts this experiment again, can she expect to have the same results?
Learn More About It
In the experiment, Susan fills a bag with 20 marbles. There are 7 blue,
2 green 4 yellow and 7 red marbles.
The possible outcomes are all the
colors Susan could pull. They are red, blue, yellow and green.
The color Susan pulls the least often is green. This color is least
likely to be pulled because there are the least number
of green marbles in
the bag. There are just 2 green marbles. If Susan does this experiment
again, the color green
remains the least likely color to be pulled.
The color Susan pulls the most often is red. There are 7 red marbles
in the bag compared to 2 green marbles and 4 yellow
marbles. However,
there are also 7 blue marbles.
If Susan were to do this experiment again, she is equally likely to pull either
red or blue marbles since there are 7
red marbles and 7 blue marbles. Since
there are 7 of each, there is an equal chance that either color could be pulled.
If Susan were to pull either a green or yellow, the yellow marble is more
likely to be pulled since there are more yellow
marbles. There are 4
yellow marbles and just 2 green marbles.
There is no chance of pulling a white marble. It is impossible since there are no white marbles in the bag.
In doing the experiment again, Susan may find the results to be close, but
they may not be the same because of the
element of chance, particularly in
pulling either the red or blue marbles more often since there is an equal number
of both.
Websites to Check Out For Extra Practice
Click on this website to review an explanation of certain, more likely, less
likely or impossible outcomes. When you
get on the site, scroll down
to Teaching Model 20.2 and click on that. Make sure to turn on your speakers.
http://eduplace.com/math/mw/models/tm_5.html
Click on this website to do similar experiments like the one in the lesson
above.
http://www.harcourtschool.com/activity/elab2004/gr4/28.html
Click on this website for a game on probability expressed as a fraction.
http://www.harcourtschool.com/activity/probability_circus/
Click on this website for short games/activities on probability. Then
select the following: Chances Are, Head I Win,
Heads Up Probability,
Lions and Tigers, Me Too Probability, On Stage Probability, Pin the Tail, What
Are My Chances and What
Should I Wear.
http://www.beaconlearningcenter.com/WebLessons/
Click on this website and then click on probability
and statistics. There
will be a lot of different interactive activities for you to
choose. Make
sure that you click on "What, Why and How" in order to understand
the purpose of the activity and how the activity works.
http://www.shodor.org/interactivate/elementary/#pro
More Instruction and Activities on Probability 
http://math.about.com/gi/dynamic/offsite.htm?site=http%3A%2F%2Fwww-math.bgsu.edu%2F%7Ealbert%2Fm115%2Fprobability%2Foutline.html
http://www.mathgoodies.com/puzzles2004/puzzles/iprobability1.html
http://www.mathgoodies.com/lessons/vol6/intro_probability.html