Update your skills. See page 27.
Events and Outcomes
7-8
The probability of an event is affected by whether the experiment
is conducted with or without replacement.
Rae put these letters into a bag. She picked
a letter at random ten times and replaced
the letter in the bag each time. Then she
graphed her results.
What conclusion can Rae draw about the
probability of picking B on the 11th pick?
Since Rae puts the card back in the bag after
each pick, the contents of the bag do not
change. So, the probability of picking B is
the same for every pick.
The probability of picking B is always ^13 .
As the number of possible outcomes changes,
so does the probability of an event.
Ben put these digits into a bag. He picked
a digit at random and did not replaceit in
the bag. He did this for each pick.
What is the probability of Ben picking 0 on
the 3rd pick?
1st Tr y:5 digits in the bag
Probability of picking 0: 1 out of 5; ^15
2nd Tr y: 4 digits in the bag
Probability of picking 0: 1 out of 4; ^14
3rd Tr y: 3 digits in the bag
Probability of picking 0: 1 out of 3; ^13
The probability of Ben picking 0 on the 3rd pick is 1 out of 3, or ^13 .
Think
The probability of picking
B on the 1st pick was
1 out of 3, or ^13 .
Number of Times Picked
0 1 2 3 4 5 6
Letter
C
B
A
After 10 Picks
Ben’s Picks
Try Digit
1st 8
2nd 6
3rd
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