1. Unit 8 Probability and Statistics Unit Review
Ch. 9 and 10

2. Test
Consists of multiple choice, true/false, and short answer all combined
Will have a few extra credit questions built in
MUST be completed by the end of the class period on Friday

3. 9-7 Independent and Dependent Events
Independent: when one event does not affect the outcome of the other event
Ex: spinning a spinner and rolling a number cube
Find the probability of each event as fraction and multiply them
Simplify answer

4. 9-7
Dependent: the outcome of the first event affects the outcome of the second event
Ex: You have a bag of marbles. You pick one marble, DO NOT REPLACE IT, and pick another one
Number of outcomes usually changes for the second event
Find the probability of the first event FIRST, then the second event and multiply them
Simplify answer

5. 9-7
There are three quarters, five dimes, and twelve pennies in a bag. Once a coin is drawn from the bag, it is not replaced. If two coins are drawn at random, find each probability. (Independent or Dependent?)
P(a quarter and then a penny)
P(two dimes)

6. 9-7
The two spinners at the right are spun. Find each probability. (Independent or Dependent?)
P(less than 5 and B)
P(odd and A)

7. Using a number cube, what is the probability of rolling a 6, then a 5?
What is the probability of flipping a coin and tails occurs four times in a row?
A jar contains 5 blue marbles, 6 yellow marbles, and 4 green marbles. What is the probability of randomly choosing a yellow marble, not replacing it, and then choosing a blue marble?

8. 9-1 Probability of Simple Events
P(event) = 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑓𝑎𝑣𝑜𝑟𝑎𝑏𝑙𝑒 𝑜𝑢𝑡𝑐𝑜𝑚𝑒𝑠 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑝𝑜𝑠𝑠𝑖𝑏𝑙𝑒 𝑜𝑢𝑡𝑐𝑜𝑚𝑒𝑠
Probability is a number between 0 and 1
Near 0 =very unlikely
Near 1 = very likely

9. 9-1 Probability can be written as fraction, decimal, or percent
Simplify all fractions
Fraction to decimal
Divide numerator by denominator
Decimal to percent
Multiply decimal by 100 (move decimal two places to right)

10. A spinner is divided into eight equal sections numbered 1-8
A spinner is divided into eight equal sections numbered It is spun once. Find each probability. Write each answer as a fraction, a decimal, and a percent.
P(not 5) P(six or less)
P(2 or 7) P(10)

11. The probability of choosing a “Go Back 1 Space” card in a board game is 25%.
If you pick a random card, what is the probability that it is not a “Go Back 1 Space” card? Explain your reasoning.
Write a sentence that explains how likely it is for a player in the game to random pick a “Go Back 1 Space” card.

12. 9-2 Theoretical and Experimental Probability
Theoretical: what should happen (what’s expected)
Experimental: what actually happens in a probability experiment
Compare the two probabilities by changing the fractions to decimals and writing a sentence
They are close because one fraction is close to the other OR
They are not close because there were not enough trials

13. The table shows the results of a number cube being rolled 40 times.
Find the experimental
probability of rolling a 5.
Find the theoretical
Compare the
experimental and theoretical
probabilities.

14. 9-2 Predict Future Events
Find the probability from the original problem
Simplify it
Set up a proportion with new total at the bottom of the second fraction and solve for the missing part

15. If a coin is flipped 150 times, about how many times would it be expected to land on heads?
If a number cube is rolled 60 times, how many times would it be expected to land on a 1?

16. 9-5 Fundamental Counting Principle
Using multiplication instead of a tree diagram to find the number of possible outcomes in a sample space
If there are more than 2 events, continue to multiply event outcomes together to determine the total number of outcomes
Show and label outcomes for each event!
If finding the probability of an event, use FCP to find the total number of outcomes (denominator)
Usually one favorable outcome (numerator)

17. Use the Fundamental Counting Principle to find the total number of outcomes for each situation.
Tossing a dime, a quarter, a penny, and rolling a number cube
Picking a number from 1 to 30 and a letter from the alphabet

18. To drink with your dinner, you can choose water, milk, juice, or tea; with or without ice; served in a glass or a plastic cup
How many different drink combinations are possible? If your drink is chosen at random, what is the probability of getting tea, with ice, in a plastic cup? Is it likely or unlikely that you would get this specific drink?

19. 9-6
Permutations
An arrangement, or listing, of objects in which order is important
Use the Fundamental Counting Principle to find the number of permutations
Once something is chosen, it cannot be chosen again
Use blanks for number of objects!
If finding the probability of an event, find the permutation (total number of outcomes) first
Usually one favorable outcome (numerator)

20. Martin has four books. In how many ways can he arrange them on his bookshelf?
There are 12 students on the basketball team. In how many ways can the coach set up the starting lineup of 5 players if John will start at one of the guard positions?

21. If there are 12 students on the debate team, what is the probability that Meghan will win first place, Eden will win second place, and Lorena will win third place?

22. 10-1
Make Predictions
Statistics: Collecting, organizing, and interpreting data
Survey: A method of collecting information
Population: The group being studied
Sample: Part of the group that is surveyed
Must be representative of the population!

23. Make Predictions Using Ratios:
Find the probability/results for the original problem/survey and write as a simplified fraction
Set up an equivalent fraction
New number/population goes on bottom
Solve by multiplying by same number across top and bottom or by using cross-products
Label answer!

24. A survey found that 17 out of 20 teens eat breakfast every morning
A survey found that 17 out of 20 teens eat breakfast every morning. What is a reasonable prediction for the number of teens out of 1,280 in a school who eat breakfast every morning?

25. A survey showed that 70% of students would select roller coasters as their favorite ride at an amusement park. Out of 5,000 students, predict how many would NOT select roller coasters as their favorite ride.

26. The table shows the results of a survey at Scobey Middle School about students’ favorite cookies.
There are 424 students
at Scobey Middle School.
About how many can be
expected to prefer chocolate
chip cookies?

27. 10-2 Unbiased and Biased Samples Unbiased = GOOD! (Valid results)
Accurately represents the entire population
Simple Random Sample
Systematic Random Sample
Biased = BAD! (Not valid results)
One or more parts of the population are favored over others
Convenience Sample
Voluntary Response Sample

28. Antwan wants to know how often the residents in his neighborhood go to the beach. Which sampling method will give valid results?
A. He asks all the members of the swim team at his school
B. He asks all his family members and friends
C. He posts a question on a community Web site
D. He asks three random households from each street in his neighborhood

29. Determine whether the conclusion is valid. Justify your answer.
To determine the most common injury cared for in an emergency room, a reporter goes to the same hospital every afternoon for one month during the summer and observes people entering the emergency room. She concludes that second degree sunburn is the most common injury.

30. To evaluate the defect rate of its memory chips, an integrated circuit manufacturer tests every 100th chip off the production line. Out of 100 chips tested, one chip is found to be defective. The manufacturer concludes that 3 chips out of 300 will be defective.

31. MMMR Mean: average of a data set Median: middle of a data set
Add the numbers and divide by how many there are
Median: middle of a data set
Put the numbers in order and cross out number on both ends until you find the number in the middle
If even amount of numbers, find the average of the middle two
Mode: number(s) that occur the most often
Range: spread of the data
Subtract the lowest number from the highest

32. The number of toys donated by students in 12 classes is shown below
The number of toys donated by students in 12 classes is shown below. Find the mean, median, mode, and range of the data.
24, 33, 59, 19, 16, 29, 20, 17, 31, 23, 16, 25

33. 10-5 Select an Appropriate Display
Bar Graph: show the number of items in specific categories
Box Plot: show measures of variation (median) for a set of data
Circle Graph: compare parts of the data to the whole (percents)
Double Bar Graph: compare two sets of categorical data
Histogram: show frequency of data divided into equal intervals
Line Graph: show change over a period of time
Line Plot: show frequency of data with a number line

34. Select an appropriate display for each situation
Select an appropriate display for each situation. Justify your reasoning.
ages of all students at a summer camp
test grades for a class, arranged in intervals

35. 10-4 Compare Populations Median: breaks data in half
First Quartile: median of first half of data
Third Quartile: median of second half of data
Interquartile Range: Third quartile – first quartile

36. You can draw inferences about two populations in a double box plot or double dot plot by comparing their centers and variations
If both sets of data are symmetric:
Use mean
If neither set of data is symmetric or one set of data is symmetric:
Use median for measure of center AND
Use interquartile range for measure of variation (spread of the data)

37. The double line plot shows the number of hours each month 2 groups of students reported that they watched TV.

38. Which of the following statements is true?
A. Group 1 has a greater median number of hours that they watched television. Group 1 has a smaller interquartile range, so the data is less spread out.
B. The mean for group 2 is larger than the mean for group 1.
C. The median for group 2 is larger than the median for group 1.
D. Both sets of data are symmetric. You should use the mean to compare the measures of center and the mean absolute deviation to compare the variations

39. The double line plot shows the number of students who attended the home games of the baseball team for two recent seasons.

40. Which of the following statements is not true?
A. The attendance for 2009 was more varied.
B. The attendance for 2010 was more consistent.
C. The attendance for 2009 peaked at 23 students.
D. The attendance for 2010 ranged from 20 to 27.

41. Compare the centers and variations of the two populations
Compare the centers and variations of the two populations. Round to the nearest tenth if necessary. Write an inference you can draw about the two populations
The double plot shows the daily attendance for two fitness clubs for one month