Samples
A _________________ is a sample that does not truly represent a population.
What is Biased Sample?
How do you solve a proportion?
Cross Multiply and Divide
How do you find the Mean of a Data Set?
Add all of the numbers and divide by how many they are.
What does IQR stand for?
Interquartile Range
The closer the dots, the _______________________
What is more consistent?
A sample in which every element in the population has an equal chance of being selected is a __________________________________________
What is Random Sample?
A survey asked 75 randomly chosen students if they were going to attend the school play. Twenty said yes. If there are 300 students who attend the school, how many tickets are sold.
80 tickets
Find the Mean in the Data Set: 3, 4, 7, 9, 5, 2
What is 5
How do you find the IQR?
Q3 - Q1
Median of upper quartile - median of lower quartile
The ___________ the box the less consistent the data is.
What is wider/longer?
A school randomly chose ten English teachers and asked them which type of juice their students would prefer. What reason best shows why this sample is biased?
Different Options:
No students
Only English Teachers
Not Enough in the Sample
A town wants to poll the adults and determine if they are providing a clean environment. There are:
250 females and 350 males
If they poll 100 of each gender, would it accurately represent the population of the town? Why or Why not
No because there are more males than females so we should sample more males.
Find the mean of the data set below:
8, 80, 10, 14, 27, 9
24.6
Find the IQR of the Data Set:
1, 5, 7, 9, 10, 12, 14
What is 7?
Would you consider the data below consistent? Why or Why not?
4, 5, 2, 7,3, 5, 5, 9, 7, 8, 6, 4, 2, 42
Yes because they are mostly clustered
A game company wants to survey gamers to determine the best game. They have 280,000 players that have bought their games. They decide to survey 120 gamers randomly. Why is this sample considered biased?
Not enough gamers asked
A metal-fabricating company produces 150,000 souvenir tokens each year. In a random sample of 400 tokens, 3 have stamping errors. Predict the total number of coins that will have stamping errors in a year.
1,125 coins will have errors
Determine the MAD of the Data Set
5, 7, 9, 11
What is 2?
Find the IQR of the Data Set below
3, 9, 11, 0, 4, 10, 8, 1
What is 7.5?
Which set is more consistent below:
A: 1,2,3, 4,5
B: 6, 8, 10, 15, 22
Set A IQR: 2
A country radio station wants to know what the most popular type of music is, so they ask their listeners to call in to say their favorite type. Is this sample random, why or why not?
Not random because they are all listening to the same radio station.
A seventh-grade student chooses a random sample of 50 out of 400 students. He finds that 7 students have traveled outside the United States. The student claims that less than 35 of the 400 students have likely traveled outside the United States. Is the student correct? Explain.
No because the proportion will predict 56 out of 400 students will travel outside the US
Find the difference of Means in the Two sets.
A: 3, 6, 9, 10, 11, 12, 12
B: 2, 5, 8, 12, 13, 14, 16
What is 1?
Who has the greater IQR and by how much?
A: 6, 5, 8, 10, 3, 7, 2
B: 9, 1, 3, 8, 6, 10, 8
Group B by 1
Which Phone Plan would you rather go with using the data below that tracks dropped calls within different customers.
Phones Plus: 25, 14, 16, 22, 10, 8, 35
United Phones: 9, 17, 16, 22, 14, 19, 7
United Phones