1. Mrs. Brown Maternity Leave
Week 5: Probability
Mrs. Brown
Maternity Leave

2. Day 1: Probability is a measure of how likely an event is to occur.
For example –
Today there is a 60% chance of rain.
The odds of winning the lottery are a one out of a million

3. Day 1: Probabilities are written as: Fractions from 0 to 1
Decimals from 0 to 1
Percents from 0% to 100%

4. Day 1:
If an event is certain to happen, then the probability of the event is 1 or 100%.
If an event will NEVER happen, then the probability of the event is 0 or 0%.
If an event is just as likely to happen as to not happen, then the probability of the event is ½, 0.5 or 50%.

5. Day 1:
When a meteorologist states that the chance of rain is 50%, the meteorologist is saying that it is equally likely to rain or not to rain.
If the chance of rain rises to 80%, it is more likely to rain.
If the chance drops to 20%, then it may rain, but it probably will not rain.

6. Day 1: The probability of an event is written:
P(event) = number of ways event can occur
total number of outcomes
Event: What you want to happen
Outcomes: All of the options
Example: rolling a 3
There is one 3 out of 6 possible outcomes
P=1/6 , , or 16.7%

7. Videos and Practice https://www.youtube.com/watch?v=AY3O_qsSnbE
P715 all
All practice work may be done with your partner and with a calculator.
If you are not behaving and focusing on the math, this privilege may be taken away by the teacher.

8. Day 2: Theoretical/ Experimental Probability
It is the likeliness of an event happening based on all the possible outcomes.
What we think will happen!
Experimental :
Experimental probability of an event is the ratio of the number of times the event occurs to the total number of trials.
What actually happens when you do the experiment.

9. Day 2: Real World Example
When asked about the probability of a coin landing on heads, you would probably answer that the chance is ½ or 50%.

10. Theoretical: This is the theoretical probability.
Imagine that you toss that same coin 20 times. How many times would you expect it to land on heads? You might say, 50% of the time, or half of the 20 times. So you would expect it to land on heads 10 times.
This is the theoretical probability.

11. Experimental Below is the results of really tossing a coin 20 times:
The experimental probability of landing on heads is 13/20= .65=65%
It actually landed on heads more times than we expected.

12. The more times the closer!
Now we will toss the coin 50 times:
Now the experimental probability of landing on heads is
26/50=.52=52% The probability is still slightly higher than expected, but as more trials were conducted, the experimental probability became closer to the theoretical probability.

13. Day 2: video and practice
Practice
P (1-12)
All practice work may be done with your partner and with a calculator.
If you are not behaving and focusing on the math, this privilege may be taken away by the teacher.

14. Day 3: More practice Review Day 1:
Get out a piece of paper, the teacher will pull up IXL lessons :
DD.1Probability of simple events
DD.2Probability of opposite, mutually exclusive, and overlapping events
DD.3Experimental probability
Work each one together as a class, take notes, you may need them for the quiz.
HW: worksheet – you may work with your partner unless teacher take away the privilege

15. Day 4: Making Predictions
If you know the theoretical probability that something will happen, you can make a prediction about future events. Watch the following video:

16. Examples:
If we found that 8 out of 30 students always rode the MTA bus. What could we predict about the number of students that would ride the MTA out of 600 students:
8/30=x/ x= x=160 students that ride the MTA
If we found that 65% of Kroger customers used the savings card. If there were 200 customers, how many used their savings card?
65/100= x/ x= 13000
x= 130 customers that use the savings card

17. Practice
P796 (1-7)
All practice work may be done with your partner and with a calculator.
If you are not behaving and focusing on the math, this privilege may be taken away by the teacher.

18. Day 5: Use your packet of notes to complete the quiz.
You have 40 minutes.
There are NO RETAKES for open note quizzes!!!