MBF3CI2-1 Experimental Probability
Experiment #1
Five red and five blue coloured tiles are placed in a bag. Without looking, two tiles are withdrawn. The two selected tiles are called an outcome. If the tiles are the same colour, the event, is considered even. If the tiles are not the same colour, the event is considered odd. The tiles are then replaced and then two more tiles are selected until 20 trials have been completed.
Predict:
How many odd results would you expect to get?
How many even results would you expect to get?
Record your predictions in the space provided.
Procedure:
One partner can pick up a bag with tiles (poker chips). Remove any extra tiles making sure you have 10 tiles, two different colours.
Conduct the experiment: Use a tally chart to record your results.
Tally / Frequency / Fraction / ProbabilityOdd
(different)
Even
(same)
How many times was your result odd? Record this as the frequency.
How many times was your result even? Record this as the frequency.
Write these results as a fraction out of 20.
Recordyour results in the table for the class data. Then record the class data in your notes.
Group / # of Odds / # of Evens / Experimental Probability of Odd =#odd/#trials / Experimental Probability of Even =
#even/#trials
Reflect Suppose you were to predict the number of odd events from five trials of the experiment. Which results would you use to make your predictions, your results or the class results? Explain your choice.
Experiment #2
Situation: The Ministry of Natural Resources wants to know the ratio of bass to carp to catfish in a lake. The ministry has asked registered anglers to keep track of the number of each type of fish they catch.
Simulation: You will use coloured tiles to simulate this method of analyzing fish populations.
Procedure:
Place 15 coloured tiles in your bag using 7 of one colour, 5 of a second colour and 3 of a third colour.
Legend: colour #1 = bass, colour #2 = carp and colour #3 = catfish
Trial Description: Without looking, draw one tile from the bag. Record the result in a tally chart. Replace the tile. Repeat until you have completed 30 trials.
Predict:
What fraction of the events do you expect to be bass? /30
What fraction do you expect to be carp? /30
What fraction do you expect to be catfish?/30
Conduct the experiment and record your results below and in the class table.
Event / Tally / Frequency / Fraction / ProbabilityBass
( )
Carp
( )
Catfish
( )
Record the class data below.
Group / # of Bass / # of Carp / # of CatfishUse the results from the class to draw a bar graph showing the number of each type of fish.
Write your experimental results as a ratio, bass:carp:catfish = .
How does this ratio compare to the ratio of the colours of tiles in the bag?
Does the simulation give a reasonable estimate of the ratio of the colours of tiles in the bag? Explain.
Reflect:Do you think the number of each type of fish caught is an accurate indicator of the actual ratio of fish in the lake? Explain.
Reflect:If you performed 100 trials instead of 30, would the estimate likely be more or less accurate? Explain.
Use your textbook to define the following terms:
Event:
Outcome:
Trial:
Probability:
Tally Chart:
Experimental Probability:
Use your textbook to complete the following statements.
It is possible to have successful trials, which gives a probability of . For example, the probability of rolling a 7 with a single dies is .
The number of successful trials can equal the number of trials. In this case, the probability is . For example, the probability of rolling a 1, 2, 3, 4, 5 or 6 on a single die is .
Probability always has a value between (certain to not happen) and (certain to happen).
Complete the following, record your answers in your notebook:
Discuss the Concepts: D1, D2, D3 on page 65.