Describing 1 Variable Data
The average of all numbers in a data set.
Add all values and divide by n
What is the mean?
An acronym to completely describe a scatterplot
DOFS
The most important thing to be aware of when conducting a survey is ___
BIAS.
Participants are assigned to treatments using a chance proces; can help interpret cause and effect.
Random Assignment
Occurs when some groups in the population are left out of the sample and leads to under-representation
Undercoverage
Be careful of the impact of large numbers! Use this measure of center when you have an outlier.
What is the median?
A scatterplot where all points are in a straight line has a correlation of ______.
+ or - 1
A non statistical question has how many answers?
One one answer!
the group that is not exposed to the treatment
Control Group
Attempts to contact EVERY individual in the entire population
Census
Minimum, Quartile 1, Median, Quartile 3, and Maximum are better known as this.
5 number summary
The distance from the predicted value in a scatterplot is called a ___________.
Residual
Asking people in the cafeteria during lunch would be an example of ____________ sampling.
Convenience sampling
An experiment in which either the subjects do not know which treatment a subject received, but the interviewer does.
Single Blind
The entire group of individuals that we want information about; the entire group you are interested in
Population
How do you prove a number is an outlier?
The IQR Rule
What impact does an outlier have on the correlation of a scatterplot?
Weakens the Correlation
What effect does increasing the sample size have on variability?
Increasing sample size will decrease variability and make your data more representative.
factors that cause differences between the experimental group and the control group other than the independent variable
confounding variables
describes an average distance of every score from the mean
Standard Deviation
= (Value - Mean) / Standard Deviation
Z-Score
How do you know if a residual plot is appropriate?
An appropriate residual plot shows no pattern or correlation.
An estimate that represents how far, at most, we expect the the sample to vary from the population.
Margin of Error.
When the probability of something happening is <0.05, it is said to be __________. It is unlikely to happen because of chance
Statistically Significant
What is the difference between between a bar chart and a histogram?
A bar chart is for categorical data and a histogram is for quantitative data.