1. CAHSEE PREP. Week 2 Statistics, Data Analysis, Probability
Valley OFL Prep Sessions

2. Mean, Median, and Mode Mean – the average of the data
Total of the values
Number of values
Median – the middle number in a set of data
(if there is an even number of data points, find the mean of the middle two points)
Mode – the value that occurs most frequently in a set of data. (It is possible to have a data set with no mode.)

3. Find the mean, median, and mode for the following data:
75, 89, 45, 99, 64, 67, 89, 102
Median (first place the data in order)
45, 64, 67, 75, 89, 89, 99, 102
Now find the middle terms, 75 and 89
Find the mean of the two numbers
so the median = 82
Mode (the number occurring most frequently) Mode = 89 this point occurs twice in the data set.

4. Find the mean, median and mode for the following data:
There is no mode for this data set.
Cars
Garage 1 2
Garage 2 15
Garage 3 23
Garage 4 6
Garage 5 1

5. Several students studied for a test
Several students studied for a test. They studied 13, 13, 0, 10, 6, and 12 hours. What was the mean, the mode, and the median of their study times?

6. Bar, Line, and Circle graphs
If a parent makes a $500 contribution, what percent is spent on computers and books?
How much does the whole circle represent?

7. Out of one dollar, how much is spent on computers and books?
What percent is spent on computers and books?

8. Line Graphs What day of the week has the highest student attendance?
The lowest attendance?

9. Bar Graphs
How many more students were enrolled in Pre-Algebra in January than in July?
How many more students were enrolled in Algebra in January than Basic Math in January?

10. Scatter Plots:
Positive Correlation: points fall closely together in a line with positive slope.
Negative Correlation: points fall closely together in a line with negative slope.
No Correlation: points are scattered around with no clustering or grouping

11. What type of correlation is this?
What do you think the value on day 15 will be?

12. Frequency Tables Frequency tables use tally marks to count responses.
How many students
use a car to go to
school?
were surveyed?
What percent of students surveyed come to school on the bus?
Transportation method to school
Number of Students
Car
Bus
Bicycle

13. Probability Probability = the chance that an event will happen
Probability of an independent event =
Number of favorable outcomes
Number of possible outcomes

14. The multiple choice test gives four answers for each question
The multiple choice test gives four answers for each question. Only one answer is correct. What is the probability that you will guess correctly?
The faces of a cube are numbered 1 to 6. What is the probability of rolling a 2?

15. Probability of a dependent event = Probability of event 1 x Probability of event 2 x …..
A bag contains 6 red candies and 6 blue candies. What is the probability of selecting a blue candy and then selecting a red candy?
Probability of a blue candy = 6/12
Probability of a red candy = 6/11
Probability of blue then red = (6/12)(6/11) = 36/132 = 3/11

16. A bag contains 10 balls numbered 1 to 10
A bag contains 10 balls numbered 1 to 10. What is the probability of drawing a 3 followed by drawing a 1?
What is the probability of tossing a coin 3 times and getting heads each time?