Show:
Sampling
Making Predictions
Appropriate Displays
Comparing Populations
Extras
100
Desiree wants to know how often the residents in her neighborhood go to the park. Which sampling method will give valid results? And why?
ANSWERS WILL VARY
100
21 out of 30 teens said they eat breakfast every morning. What is a reasonable prediction the number of teens out of 2,190 who eat breakfast every morning?
What is about 1,533 eat breakfast every morning.
100
What is an appropriate display to show the weights of tenth graders arranged by intervals?
What is a stem and leaf plot.
100
Which measure of center should you use to describe two data sets that are both not symmetric?
What is the median.
100
Which display would be appropriate for the data below? WHY? Price of regular gasoline: Year: 2005 2006 2007 2008 2009 Price: $1.36 $1.59 $1.82 $2.34 $2.67
What is line graph; The data shows the increase in gasoline prices over time.
200
Ms. Poplin put student names in a bucket and selected ten names without looking. What type of sample did she form?
What is a simple random sample
200
A survey showed that 85% of students would select Farris wheel as their favorite ride at an amusement park. Out of 4,000 students, predict how many would select Farris Wheel as their favorite ride?
What is 3,400 people.
200
The table shows the number of hours Ben spent sleeping each night for 12 nights. Which type of data display would be best for displaying the data? Hours Spent Sleeping 9 7 8 10 6 9 9 7 7 8 10 6
What is a line plot.
200
A basketball wants to know the average height of 5 players. The heights of the five players are listed below. Center 85 inches Forward 70 inches Power Forward 69 inches Shooting Guard 68 inches Point Guard 68 inches 1) What is the mean height of the basketball players? 2) How might this be misleading?
What is mean of 72; misleading because of the outlier, 72 is not near the center of the data because 4 out of 5 players are shorter than 72 inches.
200
A university has 5 dormitories for students. All of the dormitories have students of similar ages and offer the same conveniences. The director of housing wants to gather data by using a questionnaire with a sample of 150 students who live in the dormitories. What is the best way for him to gather a sample that is statistically reliable (unbiased)?
What is a stratified sample. Asking an equal amount of students from each dormitory.
300
Mrs. Shuman decides to survey the students in her classes to find out what the students at the school think about the new computers in the technology lab. Identify the following: • Population • Sample
What is • Population - Students at the school. • Sample - Students in her classes.
300
Of 350,000 registered voters, 1,200 were randomly surveyed. 12% of 1,200 said they were voting for Sandy. Predict how many of the registered voters (out of 350,000) would vote for Sandy.
What is 140,000 people will vote for Sandy
300
Which type of data display would be best for showing the results of a survey on students’ favorite genre (category) of movie?
What is bar graph.
300
Use the data set $21, $21, $14, $16, $20, $13, $22, and $15. Which measure of center would you use to convince people that the prices are high?
What is the mode of 21.
300
Find the Mean Absolute Deviation 5, 12, 19, 4, 23, 33
What is 9
400
Determine which sampling method will better represent the entire population. Justify your answer. Frank surveys 40 moviegoers by randomly choosing their names. 60% like the movie. Linda surveys 100 moviegoers that entered the movie theater in the first hour. 80% like the movie.
What is FRANK because it is a random sample of all of the people. Linda is surveying for only the first hour. Linda's survey is a convenience sample.
400
A survey in one middle school showed that 3 out of 7 students enjoy biking on the weekends. Predict how many out of the 483 students in the school would say they enjoy biking on the weekends.
What is 207 ride bikes on the weekend
400
Katie and Danielle recorded their resting heart rates each morning for ten days. Katie's heart rates: 57, 58, 59, 63, 65, 65, 66, 70, 71, 75. Danielle's heart rates: 67, 68, 70, 70, 71, 71, 72, 72, 73, 74. Answer the following: • Whose heart rate is more varied? • What is Danielle’s peak heart rate? • What is Katie’s peak heart rate? • What is Danielle’s average resting heart rate? • What is Katie’s average resting heart rate?
What is • Whose heart rate is more varied? Katie's • What is Danielle’s peak heart rate? 74 • What is Katie’s peak heart rate? 75 • What is Danielle’s average resting heart rate? 70.8 • What is Katie’s average resting heart rate? 65.9
400
Identify the outlier in the data set: 5, 10, 4, 7, 12, 78, 15 Then, find the mean and median WITH AND WITHOUT the outlier. If necessary, round your answers to the nearest tenth.
What is -WITH- mean 18.7 and median 10. WITHOUT - mean 8.8 and median 8.5.
400
A news show asks viewers to participate in an on-line poll to determine which segment of news their viewers enjoy the most. 1) What kind of sampling method is this? 2) Will it lead to biased or unbiased results? Explain
What is voluntary sampling; biased results; explanations vary
500
A pet store owner wants to know what type of pet food her customers prefer. At the bottom of each receipt, she provides a phone number for customers to call in and answer survey questions. Of the 94 responses, she found that 9 prefer organic pet food. 1) What sampling method did she use? 2) Are her results valid (unbiased)? Explain
What is voluntary sampling; not valid, biased; explanations will vary
500
Three types of number dice are used in a board game. All of them have one digit on each face. Each number die can land on any face with equal likelihood. • The numbers 1 through 7 are on the faces of the blue number die. • The numbers 1 through 14 are on the faces of the orange number die. • The numbers 1 through 21 are on the faces of the pink number die. In the board game, a player gets an extra turn if any of the dice lands on a multiple of 3. Arrange the number dice from least likely to most likely to result in an extra turn.
What is pink, orange, then blue.
500
How may some graphs be misleading?
What is ANSWERS MAY VERY.
500
1) What are the 3 measures of center and how do you find them? 2) Describe the effect an outlier has on the measures of center. 3) What measure of center should you use if an outlier is present?
What is 1) mean - add all values and divide by the number of values; median - order numbers from least to greatest and find the one in the middle; mode - occurs the most often. 2) an outlier mainly affects the mean. If the outlier is the largest in the data set, it will make the mean look bigger. If the outlier is the smallest in the data set, it will make the mean look smaller. 3) use the median when an outlier is present.
500
The data shows the number of hours each month 2 groups of students reported that they watched TV. Group 1 - 32, 33, 33, 35, 35, 35, 37, 37, 38. Group 2 - 20, 23, 25, 26, 27, 27, 28, 28, 30. Answer the following questions: • What is the median for each group? Which group has a greater median? • What is the interquartile range for each group? Which group has a smaller interquartile range? • What is the mean for each group? • Are the sets of data symmetric? How do you know?
What is • What is the median for each group? G1-35, G2-27 Which group has a greater median? G1 • What is the interquartile range for each group? G1-4, G2-4 Which group has a smaller interquartile range? They are the same. • What is the mean for each group? G1 - 35, G2 - 26 • Are the sets of data symmetric? How do you know? No.