Warm-Up• Find the Mean Median and Mode of the following

data sets:1. 12, 10, 9, 11, 12, 5, 7, 9, 8, 10, 15, 9, 62. 12, 10, 9, 11, 12, 5, 7, 9, 8, 10, 15, 9, 6, 27, 14. Find the mean, median and mode and range of

these test scores:54, 65, 55, 78, 23, 32, 58, 95, 75, 75, 68

5. Draw a Box and Whisker Plot of this classes test scores.

Homework Due Today

• Find the product. Write your answer using only positive exponents.

1. (5-4)(57) 2. (11-2)(11-4) 3. (x-12)(x5)

• Approximate the square root to the nearest integer.4. -√10 5. √68 6.√145

Homework Due tomorrow• A survey was conducted to find the percent of Americans

who enjoy camping. The surveyor randomly selected 20 individuals from each of the 50 states and asked, “Do you enjoy, greatly enjoy, or not enjoy camping in the woods, where the air is fresh and clean?” How much should you trust the results of the survey?1. Identify the sampling method and

populations.2. Do you think the sample chosen was

representative of the population? Explain.3. Do you think the question is biased? If so,

explain how it would affect the results of the survey?

Samples and Surveys

Monday February 21, 2011

Today I can…

• classify data and analyze samples and surveys.

Stop-and-Jot

• Think of a question that you would like to ask the entire school!

• How long would it take to pose the question to everyone in the school?

• Hypothesize different ways that you can conduct a fair survey that would not include every student at the school.

Recall: Organizing Data

• Frequency Table• Stem-and-Leaf Plot

Recall: Displaying DataType of display

Type of data Horizontal axis

Vertical axis

Histogram Numerical data

Numeric range Frequency

Bar graph Categorical data

categories Frequency

Line graph Change over time

time The thing that is changing

Box-and-whisker plot

numerical Range of numeric values

N/A

Samples and Surveys

• Population: The ____________ being studied.

Samples

• Sample: The ___ ____________being studied.

• Biased Sample: A sample that is not a good representation of the ___________.

Identifying Biased Samples

• A radio station manager chooses 1500 people from the local phone book to survey about their listening habits.

• An advice columnist asks her readers to write in with their opinions about how to hang the toilet paper on the roll.

• Surveyors in a mall choose shoppers to ask about product preferences.

Sampling Methods

• Random sample: every member of the population has __________________ of being chosen.

• Systematic sample: According to a ____ or a ____________.

• Stratified sample: At __________ from randomly chosen ______________.

Identify the sampling method used

• An exit poll is taken of every tenth voter.• In a statewide survey, five counties are

randomly chosen and 100 people are randomly chosen from each county.

• Students in class write their names on strips of paper and put them in a hat. The teacher draws five names.

Practice

• Timed Guided Practice

#1• Identify the population

and sample. Give an example of why the sample could be biased:

• A record store manager asks customers who make a purchase how many hours of music they listen to each day.

Population Sample Bias?

#2• An eighth-grade student council member polls

classmates about a new school mascot.

Population Sample Bias?

#3

• Identify the sampling method used:• In a county survey, Democratic Party

member whose names begin with the letter D are chosen.

a. Biasedb. Randomc. Systematicd. Stratified

#4

• A telephone company randomly chooses customers to survey about its service.

a. Biasedb. Randomc. Systematicd. Stratified

#5

• A high school randomly chooses three classes from each grade and then draws three random names from each class to poll about lunch menus.

a. Biasedb. Randomc. Systematicd. Stratified

#6

• Choose the best way to display this data:

• Favorite Food

a. Line graphb. Bar graphc. Histogramd. Box-and-whisker plot

#7

• Gas prices over the last month.a. Line graphb. Bar graphc. Histogramd. Box-and-whisker plot

# 8 What type of data does a bar graph show?

#9 What type of data does a line graph show?

Mean, Median, Mode

# 10 What is the mean of the following set of data:

• 1,1,2,3,4,5,5,5,6,6,7

• #11 What is the median?

#12 What is the mode?

# 13 What is the range?

#14 list the 5 elements of a box-and-whisker plot.

Choice boardFor at least two types of

data: write a 2-3 question survey. Make a hypothesis about the results, tell me what type of display you would use, justify your

reasoning and determine the population**

Make a PowerPoint presentation on organizing

and displaying data.Be sure to use key

vocabulary words and give plenty of examples!**

Practice problems out of the text book and practice book (Page 176 1-13, Page 177

19 and 20, practice exercises 4-1) *

Write 5 word problems or scenarios that are

examples of biased samples.

Write 5 that are examples of unbiased samples.**

Wild Card! Journal entry: write a 2-3 page journal entry about organizing and displaying data. Include appropriate

vocabulary, common mistakes, examples in your

journal.***

Answer a question comparing two sets of data,

represented by Box-and-whisker plots and given the

context of the data collection.**

Create a picture book or a brochure about creating

affective surveys, making a hypothesis, organizing the data, and displaying and

analyzing the data. *

Write a lesson on surveys and samples, create a

hands-on activity that would engage your students and help them to understand survey samples and data

collection.***

Exit Ticket• Identify the population and sample. Give a reason why the

sample could be biased.• 1. A high school principal asks the first three people who leave

the school play whether they liked it.

• Identify the sampling method used.• 2. At a baseball game, 10 sections are chosen at random and 10

random people from each section are polled.

• 3. A telemarketer calls the people that have a last name beginning with H.