What are measures of center? List 3 measures of center.
What are values at the center or middle of a data set? Examples: Mean, Median, and Mode.
100
The weights of all the students in grade 9 are arranged from least to greatest. Which statistical measure separates the top half of this set of data from the bottom half? 1)mean;
2) mode; 3) median; 4) average
What is choice 3 (the median)?
100
You chose a random sample of 10 students of the 7th graders in your room. If 3 of them like to dance, how many students can you predict who will like to dance from your classroom of 30 students?
What is 9
100
A random sample of 10 data values is taken: {2, 3, 7, 15, 30}. Explain which one, the mean or the median, will provide a better conclusion about the population.
What is the median because most values are closer to 7 than 30?
100
1. A sports writer wants to know which is the most popular college basketball team. Which group of people would give her the least biased answer?
A. every 4th person entering a college dining all
B. every 4th student at a freshman orientation
C. every 4th person entering a grocery store
What is C
200
Define Median and Mode
Median is the middle number of a data set
Mode is the number that occurs the most in a set of data
200
Which statement is true about the data set 3, 4, 5, 6, 7, 7, 10? 1) mean = mode; 2) mean > mode; 3) mean = median; 4) mean < median
What is Choice 3?
200
A random sample of 50 students from HSMS were sampled. This represented 10% of the population. 30 of the students from the sample did not like the cafeteria food. Predict how many students will not like the cafeteria food of the total students population.
What is 500
200
What is the best measure of center to use?
A basketball team's points in the last 7 games: 35, 82, 91, 76, 88, 100, 111
Median
200
Identify three things that create bias in a survey.
What is
1. Convenience sampling
2. Voluntary Response
3. Small Sample Size
4. Undercoverage
5. Leading questions
6. Nonresponse
300
What is the range?
The difference between the maximum and minimum in a data set
300
Find the range and outliers from the following exam scores: 87, 56, 57, 65, 34, 66, 75, 67, 87, 99, 84, 73, 79, 80
What are Range = 65 and Outliers: 34 and 99?
300
Abubakar randomly selected 60% of the seventh-grade students in his school and asked them their favorite subject. Of the students surveyed, 24 chose Math as their favorite subject. Based on the data, what is the most reasonable prediction of the number of seventh-grade students in his school who would choose Math as their favorite subject?
What is 40
60/100 = 24/x where x shows the total number of students surveyed. x would equal 40. If there are 40 people surveyed in total then finding the remaining percent of the 7th grade students and adding that prediction with the 24 should give the entire population's prediction.
40/100 = x/40 so x = 16 students that prefer math
16 + 24 = 40
Shortcut: 60/100 = 24/x and because 100 could also represent 100% of the 7th grade, this is our answer
300
Which of the following is a statistical question? You may choose more than one.
A) Do you like to sleep?
B) How tall are you?
C) How many shirts do you own?
D) What pet do people in your neighborhood prefer?
What is D
300
A school wants to add a coed soccer program. To determine student interest in the program, a survey will be taken. In order to get a random sample, which group should the school survey? A) every third student entering the building; B) every member of the varsity football team; C) every member in Ms. Zimmer’s drama classes;
D) every student having a second-period French class.
What is choice A?
400
What is an outlier? How does it affect the center of the data?
An outlier is a number that is not consistent with the rest of the data - it is far away from the majority of the rest of the data.
The outlier affects the mean by making it higher or lower due to how far the outlier is away from the rest of the data. The outlier does not affect the mode and usually affects the median very minimally.
400
Mr. Vargas is trying to compare the exam scores of his 7th grade classes. He chose some students from both 1st and 2nd block. The scores for 1st block were: 65, 85, 75, 90, 82, and 95.
The scores for 2nd block were: 75, 74, 71, 95, 99, 85 and 75. What conclusion can Mr. Vargas reach about his two classes? A) 2nd block had a higher median score than 1st block. B) 71M had a higher mean than 2nd block. C) 1st block had a greater range than 2nd block. D) 2nd block had a greater mean absolute deviation than 1st block.
What is C
400
Kristi pulled a handful of marbles from a bag and sorted them by color. She saw that there were 4 green, 2 red, and 1 blue marble in the bag.
Using the sample data above, what do you predict the total number of marbles to be if there are a total of 26 red marbles in the bag?
What is 91
400
Which of the following is a statistical question? You may choose more than one.
A) How many words are there in the Pledge
of Allegiance?
B) How many hours per day do students in
this class spend playing video games?
C) How many miles do the teachers in our
school travel to work each day?
D) What is your favorite type of soda?
What is B and C
400
Identify the problems with the below research proposal:
I want to determine how many middle school students in the United States play video games. I plan to post a survey on Ms. Price's website and request for students in 1st block to fill it out.
What is
Small Sample Size: One class does not represent the entire US.
Voluntary Response: You are requesting the students to fill out the online survey instead of randomly choosing participants.
Convenience Sampling/Undercoverage: Only students with the internet will be able to respond you are eliminating part of your population
500
What are the requirements to have a good sample?
It must be random to prevent bias and allow each sample participant an equal chance of being chosen. It must have a large enough sample size. It must be based on the target population.
500
Find the mean absolute deviation of the following set of data: 23, 24, 22, 30, 25, 26, and 32. Round the answer to the nearest tenth.
What is 2.9?
500
Cara looks through her 74 TV stations and finds that she has 28 cartoon channels, 12 news channels, 18 movie channels, 6 sports channels, and 10 comedy channels. With Cara's TV package, she owns 60% of all possible channels. How many movie channels would Cara be expected to have if she purchased the rest of the channels?
What is 30?
500
What is the best measure of center for the following data?
The number of characters in the Tweets for the day: 120, 125, 120, 200, 100, 120, 5, 140, 120
What is mode?
500
Four hundred licensed drivers participated in the math club's survey on driving habits. These were the age groups and the number of the participants: 16-25 years old = 150; 26-35 years old = 129; 36-45 years old =33; 46-55 years old = 57 ; 56-65 years old = 31. A) It may be biased because no one younger than 16 was surveyed.
B) It would be fair because many different age groups were surveyed. C) It would be fair because the survey was conducted by the math club students. D) It may be biased because the majority of drivers surveyed were in the younger age intervals.