lesson 10.1

1. A day of the week is selected at random and a number cube is rolled. Find
each probability.
1. P(begins with “S” and 4)
2. P(Wednesday and 3)
A bag of pencils has 3 red, 5 blue, and 8 yellow pencils. Find each probability
if each pencil selected is not returned to the bag.
3. P(red then blue)
4. P(2 yellows)
5. Jordan makes 75% of his basketball free throws. What is the
probability that he will make 4 free throws in a row? Write your
answer as a percent.
6. Josh flips a coin and draws a card from a deck of 52. What is the
probability that he will flip heads and draw a seven?
Course 2, Lesson 10-1

2. Course 2, Lesson 10-1
ANSWERS
1. 2.
3. 4.
5. 32% 6.
1
21
1
42
1
16
7
30
1
26

3. HOW do you know
which type of graph to use
when displaying data?
Statistics and Probability
Course 2, Lesson 10-1

4. Course 2, Lesson 10-1 Common Core State Standards © Copyright 2010. National Governors Association Center for Best Practices and
Council of Chief State School Officers. All rights reserved.
Statistics and Probability
• 7.SP.1
Understand that statistics can be used to gain information about a
population by examining a sample of the population;
generalizations about a population from a sample are valid only if
the sample is representative of that population. Understand that
random sampling tends to produce representative samples and
support valid inferences.
• 7.SP.2
Use data from a random sample to draw inferences about a
population with an unknown characteristic of interest. Generate
multiple samples (or simulated samples) of the same size to gauge
the variation in estimates or predictions.

5. Course 2, Lesson 10-1 Common Core State Standards © Copyright 2010. National Governors Association Center for Best Practices and
Council of Chief State School Officers. All rights reserved.
Statistics and Probability
Mathematical Practices
1 Make sense of problems and persevere in solving them.
3 Construct viable arguments and critique the reasoning of others.
4 Model with mathematics.

6. • To make predictions using
ratios
• To make predictions using
equations
Course 2, Lesson 10-1
Statistics and Probability

7. Course 2, Lesson 10-1
Statistics and Probability
• statistics
• survey
• population
• sample

8. Need Another Example?
Step-by-Step Example
1. What is the probability that a student brought a photo
taken at a theme park?
The students in Mr. Blackwell’s
class brought photos from their
summer break. The table shows
how many students brought each
type of photo.
1
2
P(theme park) = =
So, the probability of a theme park photo is .

9. Answer
Need Another Example?
Every sixth person in the school cafeteria was
asked to name where he or she would like to go
for the school’s spring outing. Fifteen chose an
amusement park, 10 chose a baseball game, 10
chose a water park, and 5 chose an art
museum. What is the probability that a student
prefers to go to an amusement park?

10. Need Another Example?
Step-by-Step Example
2. There are 560 students at the school where Mr. Blackwell teaches. Predict
how many students would bring in a photo taken at a theme park.
The students in Mr. Blackwell’s
class brought photos from their
summer break. The table shows
how many students brought each
type of photo.
1
2
3
4
5
Let s represent the number of theme park photos.
Of the 560 students, you can expect about 220 to bring
a photo from a theme park.
Write an equivalent ratio.
Since 28 × 20 = 560,
multiply 11 by 20 to find s.
s = 220.

11. Answer
Need Another Example?
The probability that a student prefers to go to an
amusement park is . Suppose there are 408
students at Julia’s school. Predict how many
students prefer going to an amusement park.
about 153 students

12. 1
Need Another Example?
2
3
4
Step-by-Step Example
3. A survey found that 85% of people use emoticons on
their instant messengers. Predict how many of the 2,450
students at Washington Middle School use emoticons.
n = 0.85 · 2,450
Words
Variable
Equation
What number of students is 85% of 2,450 students?
n
Let n represent the number of students.
Write the percent equation.
n = 2,082.5 Multiply.
About 2,083 of the students use emoticons.
= 0.85 ● 2,450

13. Answer
Need Another Example?
According to one survey, 25% of high school students
reported that they would not get summer jobs. Predict
how many of the 948 students at Mohawk High School
will not get summer jobs.
about 237 students

14. 1
Need Another Example?
2
3
4
Step-by-Step Example
4. The circle graph shows the
results of a survey in which
children ages 8 to 12 were
asked whether they have a
television in their bedroom.
Predict how many out of 1,725
students would not have a
television in their bedroom.
You can use the percent equation and the survey results to predict
what part p of the 1,725 students have no TV in their bedroom.
Survey results: 54%
p = 931.5 Multiply.
About 932 students do not have a television in their bedroom.
part = percent · whole
p = 0.54 · 1,725

15. Answer
Need Another Example?
The table shows the results of a survey in which
people were asked whether their house pets
watch television.
There are 540 students at McCloskey Middle
School who own pets. Predict how many of
them would say their pets watch TV.
about 205

16. How did what you learned
today help you answer the
HOW do you know
which type of graph to use
when displaying data?
Course 2, Lesson 10-1
GeometryStatistics and Probability

17. How did what you learned
today help you answer the
HOW do you know
which type of graph to use
when displaying data?
Course 2, Lesson 10-1
GeometryStatistics and Probability
Sample answers:
• To use ratios to make predictions based on the results
shown in a table
• To use equations to make predictions using the results
shown in a data display

18. If 16 students in this class
chose math as their favorite
subject, what is P(math)?
Course 2, Lesson 10-1
Ratios and Proportional RelationshipsFunctionsStatistics and Probability