Biased or Unbiased
Random Sampling
Population & Samples
Predictions
Interpreting Data
Mixed Review
100
A clothing store, Forever 22, wants to know about how many people go to Forever 22 in the mall in comparison to other stores in the mall. So they asked every 10th person entering the mall. Is this bias or valid?
What is valid?
This is systematic random. Asking at the mall is appropriate since that is where any potential customers would be. If they were asking people already at their store, THEN it would be biased.
100
A person is surveying how many people go to Starbucks. So every Randomly 10th person is surveyed. What type of sampling method is this?
What is Systematic
100
A company wants to know about how much do all of America's Families use its technology, but it would take years, so they sampled 1000 people.
Who is the population...
What is All of America's Families
100
This type of equation is used to make predictions in Math. (the first letter of the word is P)
What is a proportion?
100
The range of Marcella's quiz scores is 20. The range of Isra's quiz scores is 30. What can you infer?
A) Marcella does better on quizzes
B) Isra does better on quizzes
C) Marcella's quiz scores are more consistent
D) Isra's quiz scores are more consistent
What is (C)?
A large range indicates the variance of scores. Marcella's range was smaller, meaning her scores were closer together and more consistent.
100
A spinner is split into 9 equal sections, labelled 1, 2, 3, 4, 5, 6, 7, 8, and 9.
What is the probability of randomly spinning a number greater than 7?
2/9
200
A Student wants to know who the favorite teacher is in their pod. They survey their 2nd period. Biased or representative?
What is Biased
200
Mrs. Ima Teecha wants to know how long her students spend studying for tests. She puts the names of all her students on slips of paper, in a jar, and randomly chooses 20 to survey. What type of sampling method is this?
What is simple random?
200
A boy wants to know about how much of all of his grade level plays board games. So, he surveyed 35 kids in his grade level.
Who is the population...
What is All of The Grade Level
200
Erick is running for student council Vice President and wants to know how many students at the school plan on voting for him. He decides to randomly survey 10 people in his homeroom. 8 of the students said they were voting for him.
If there are 1,000 students in the school, this is the amount of students you expect to vote for Erick.
What is 800?
200
Which of the following is a true statement?
A) Ladybugs tend to be longer
B) Beetles vary more in size
C) All beetles are larger than all ladybugs
D) There were less ladybugs in the sample
What is B?
The box plot for Beetles is much larger, indicating a larger variance/spread.
200
Write as a decimal: 3%
0.03
300
A lemonade stand wants to know how many people get or drink lemonade. So, every person that goes to the stand will be surveyed.
What is Biased
300
A 7th grader Wants to know what is 7th graders Favorite Ice cream. So, the 7th grader puts up fliers around the 7th grade hallways with a QR code linked to a survey for students to complete. What type of sampling method is this?
What is voluntary?
300
A girl wants to know how much time her friends spend time on the phone. So, she surveyed 5 of her friends.
Who is the sample...
What is 5 of her Friends
OR
What is the 5 friends she surveyed
300
Akinah surveys 21 Georgians to see what their favorite color is. The results are recorded in the table below.
Out of a group of 65, about how many Georgians would you expect to choose yellow as their favorite color?
What is 9 people/Georgians?
(9.28 is the calculated answer, but we round to 9 since the question is asking about the number of people. You cannot have 0.28 people)
300
This is the difference in the medians for spring and summer temperatures.
What is 10?
(80 - 70)
300
Laila is choosing between a brown shirt and a red shirt, blue pants, black pants, or white pants. How many total combinations of outfits are possible?
6
400
A Girl (4th grader) wants to know about how many people in 7th grade wear make-up at Five Forks. So, she surveyed every 5th 7th grade student from a roster of the 7th graders in the school. Valid or biased?
What is valid?
400
A Old Man wants to know about how many old people can still run. So, he randomly surveys every 5th old person. What type of sampling method is this?
What is Systematic
400
A boy wants to know his math class students average grade in math. So, he surveyed 5 students in the class.
Who is the population...?
What Is All of his Math Class Students.
400
Joseph asks 20 people what their favorite animal is and 5 of those surveyed state that a monkey is their favorite animal.
About how many people will choose a monkey as their favorite animal out of a group of 75?
What is 19 people?
(18.75)
400
Braeden went to one of the above restaurants and purchased a meal for $10. This is the restaurant Braeden most likely went to.
What is the Red Brick Grill?
400
Two dice are rolled. What is the probability they sum to 12?
1/36
6+6 = 12 is the only combination
500
Chase wants to know about how many people in his community play sports. So, he surveyed every 5th person who enters a sports store. Biased or representative?
What is Biased?
Though it is systematic, he is at a SPORTS STORE asking if they play a sport; so they are more likely to say yes.
500
A restaurant wants to know how often their customers buy breakfast. They survey the first 20 customers they see. What type of sampling method is this?
What is Convenience
500
Andrew wants to know about how many people spend their time outdoors in his county. So, he sends a survey in the mail to every resident in his county and asks them to complete and return to him.
Who is the sample...
What is the people in the county who actually take the mail survey?
OR
What is the people who respond?
500
Kyla wants to know how many 7th grade students have their own cell phone. She surveys 40 students, and 32 of them own a cell phone.
If there are 500 7th graders, this is the amount that you would expect to own a cell phone.
What is 400?
500
Which of the following is true?
A) The restaurants have the same range of prices
B) The meals at Red Brick are more expensive
C) The restaurants have the same median price
D) The restaurants have the same interquartile range of price
What is D?
(Recall: the IQR/interquartile range is Q3-Q1, this it the length of the "box" ) Both restaurants have an IQR of 2.
500
5 pens are in a box (2 red, 2 black, and 1 green). What is the probability you randomly choose a black pen first, do not replace it, and then choose a another black pen?
What is 1/10?