Population
Type of Variables
Valid sample?
Spread parameters
Statistical parameters (position and concentration)
100
What is population?
The entire collection of people or entities of interest
100
What type of variable is hair color?
qualitative
100
We want to know how many Spaniards speak English. Would you use a sample? Why?
yes, because the population of Spain is too large to study every Spaniard.
100
I survey the class regarding the results on a recent exam. The results are as follows: 10: 1 student 9: 3 students 8: 6 students 7: 12 students 6: 7 students What is the range?
4
100
What is mean?
The sum of all the values divided by the population, N
200
What is the difference between population and sample?
The population is all of the people or entities of interest, whereas the sample is a part of the population that represents the whole population.
200
You want to know how many people like pop music. What type of variable are you studying?
qualitative
200
We want to know how many Spaniards speak English. What sampling method would you use?
(answers will vary)
200
What is absolute deviation?
How far an individual value is from the mean of the set
200
I survey the class regarding the results on a recent exam. The results are as follows: 10: 1 student 9: 3 students 8: 6 students 7: 12 students 6: 7 students What was the mean mark?
7
300
A proposal before the state parliament would increase the gasoline tax. The additional money would be used to improve the state's roads. Some state legislators are concerned about voters' opinions. To gain this information, they randomly select 1,009 registered voters and ask them if they favor the additional tax. What is the population?
all the registered voters in the state
300
A proposal before parliament would increase the gasoline tax. The additional money would be used to improve the state's roads. Some state legislators are concerned about voters' opinions. To gain this information, they randomly select 1,009 registered voters and ask them if they favor the additional tax. What type of variable is this?
qualitative
300
We want to know how many Spaniards speak English. I walk down the street and ask people questions in English. Is this a valid sample? Why or why not?
no, because this sample does not represent the overall population
300
I survey the class regarding the results on a recent exam. The results are as follows: 10: 1 student 9: 3 students 8: 6 students 7: 12 students 6: 7 students What is the absolute deviation of the marks for the students who got a 10?
3
300
I survey the class regarding the results on a recent exam. The results are as follows: 10: 1 student 9: 3 students 8: 6 students 7: 12 students 6: 7 students What are the median and the mode?
7 median, 7 mode
400
A proposal before parliament would increase the gasoline tax. The additional money would be used to improve the state's roads. Some state legislators are concerned about voters' opinions. To gain this information, they randomly select 1,009 registered voters and ask them if they favor the additional tax. What is the sample?
1,009 registered voters
400
A proposal before parliament would increase the gasoline tax. The additional money would be used to improve the state's roads. Some state legislators are concerned about voters' opinions. They want to know how much gasoline voters consume each week. They randomly select 1,009 registered voters and ask them if they favor the additional tax. What type of variable is this?
Continuous quantitative variable
400
A proposal before parliament would increase the gasoline tax. The additional money would be used to improve the state's roads. Some state legislators are concerned about voters' opinions. To gain this information, they called every third person listed in the phone book. Is this a valid sample? Why or why not?
No, because the people in the phone book are not all voters
400
Identify this equation and explain what it means: CV = σ/μ
This is the coefficient of variation, and it is the standard deviation divided by the mean
400
I survey the class regarding the results on a recent exam. The results are as follows: 10: 1 student 9: 3 students 8: 6 students 7: 12 students 6: 7 students How many students are in the 90th percentile?
26.1
500
A proposal before parliament would increase the gasoline tax. The additional money would be used to improve the state's roads. Some state legislators are concerned about voters' opinions. To gain this information, they randomly select 1,009 registered voters and ask them if they favor the additional tax. They sampled one out of every eight people. What is the population?
8,072 people
500
We want to know how many people speak English in Spain. What is the population? What is the variable? Which type of variable is it?
Population: all people in Spain Variable: ability to speak English Type of variable: Qualitative
500
A proposal before parliament would increase the gasoline tax. The additional money would be used to improve the state's roads. Some state legislators are concerned about voters' opinions. To gain this information, 1,009 registered voters are asked if they favor the additional tax. To gather that sample, they selected every third voter in the voter database. What type of sampling method is this? Is it valid? Given the sample, how many voters are in the population?
Systematic sampling; yes; 3,027
500
What is standard deviation? Write the formula.
It is the square root of the variance.
500
I survey the class regarding the results on a recent exam. The results are as follows: 10: 1 student 9: 3 students 8: 6 students 7: 12 students 6: 7 students What are Q2 and Q3?
Q2 is 7, Q3 is 8
M
e
n
u