Chapter 1 Test Flashcards
Residual Equation
4th Residual;
R4 = y4 - [f(x4)]
What is the correlation coefficient and what does it provide
The “r” value and provides direct (+ or -) and the strength
What is the coefficient of determination and what does it tell
It is the “r^2” value. It shows the strength. The percentage shows the percentage of variance in the “y” that’s a result of the variance in the “x”
How to convert “r” to “r^2”
Square the “r” value
How to convert “r^2” to “r”
You square root the “r^2”
What is a class interval
Spread of values within an individual category
What is a frequency table used to do
List variables and their frequency
6 discrete/categorical graphs
- Frequency table
- Stem-Leaf graph
- Pictograph
- Bar graph
- Scatter plot
- Circle graph
3 Continuous graphs
- Histogram
- Broken line Graph
- Circle Graph
What is a sample and what is the minimum percent of population required to be surveyed
Part of population used to collect info about the whole population and minimum of 20%
What is a Casual Relationship
When one variable directly affects the other
What is a census
When you ask everyone in a population rather than a sample
2 things about making a Thesis
- NEVER say “clearly seen”, act like u haven’t seen the data
- Compare variables rather than people
What is the range for a STRONG correlation
0.7
What is the range for a WEAK correlation
0.3
Cross sectional study
Study that considers individuals from different groups at the same time
Longitudinal study
Study of a single group (or sample) over a long period of time
Time series data
Data that has been accumulated over a long period of time
Quantitative variables
Variables that can be measured numerically
Qualitative variables
variables that can’t be measured numerically
Discrete data examples
- Number of people
- Number of cars
Examples of categorical
- “people that like school”
- “people that like the colour blue”
Examples of continuous
- weight
- age
- time
What is random sampling and why is it used
Sampling occurring by chance and is used to minimize bias
How to find sampling interval
Population size / Sample size
What are the 6 Random Sampling Techniques
- Simple
- Systematic
- Stratified
- Cluster
- Multi-Stage
- Destructive
What is Simple Random Sampling
Where all people within the population are equally likely to be selected to be used in the sample group
What is Systematic Random Sampling
HELP
What is Stratified Random Sampling
Divides population into groups called “strata”, a simple random sample is then taken from each stratum
What is Cluster Random Sampling
Organizes population into groups and then entire groups are randomly selected
What is Multi-Stage Random Sampling
Organizes population into groups and then a Simple Random Sample is taken from randomly selected groups
What is Destructive Random Sampling
Requires that the samples that are taken are destroyed in the process of testing (cars in crash tests)
What is “Bias”
An in intended influence in a data gathering method
4 Types of Bias
- Sampling Bias
- Non-Response Bias
- Household Bias
- Response Bias
When asked for “types of variables” what is it asking for?
Asking whether it is discrete, categorical, or continuous
What must you include in an Analysis
- “r” value
- the word Strong, Weak, or No Correlation
- whether it is positive or negative correlation
- the percentage of relationship “r^2”
- mention the residuals to help prove the correlation to be strong or weak
- Use “after collecting the data” rather than “after taking the survey”
