# Shared Flashcard Set

Intro to Stats
Test Review 1
32
Mathematics
12/05/2012

## Additional Mathematics Flashcards

Term
 What is the difference between Numerical and Categorical Variables?
Definition
 Quality and Quantity
Term
 What is a two-way table?
Definition
 Used for categorical varibles
Term
 Observational Study?
Definition
 Watching, not controlling variables
Term
 Controlled Experiment?
Definition
 Researchers choose groups randomly
Term
 What are the 3 ways to display Numerical Distribution?
Definition
 1. Histogram 2. Dot plot 3. Stem plot 4. Box plot
Term
 What are the 3 features discusses for Numerical Distribution?
Definition
 1. Shape (symmetrical, bimodal, unimodal) 2. Spread (IQR or Range) 3. Center (Median)
Term
 What are the 2 ways to display Categorical Distribution?
Definition
 1. Bar Chart 2. Pie Graph
Term
 What are the 2 features of a Categorical Distribution?
Definition
 1. Variability (diversity) 2. Mode (thing that occurs the most)
Term
 3 shapes in Mean vs Meadian in skewed distribustion
Definition
 1.Mean=Meadian→symmetric 2. Mean>Median→right-skewed 3.Mean
Term
 What is IQR?
Definition
 Interquartile Range, how spread out the middle 50% of data is (measure of spread) -Q3-Q1
Term
 What measures are resistant to outliers?
Definition
 1. Median (center) 2. IQR (spread)
Term
 What are the 4 features used to describe a scatterplot?
Definition
 1.Trend (positive or negative) 2.Strength (weak or strong) 3.Shape (liner or not) 4. Outliers
Term
 How do we find potential outliers?
Definition
 Any point 1.5XIQR away from Q1 or Q3(edges of the box)
Term
 What is the Five Number Summary?
Definition
 1.Min 2.Q1 3.Median 4.Q3 5.Max
Term
 Treatment Variable
Definition
 Type of letter groupings (x)
Term
 Response Variable
Definition
 # of letter memorized (Y)
Term
 What is the Emperical Rule?
Definition
 The rules gives the approximate % of observations w/in 1 standard deviation (68%), 2 standard deviations (95%) and 3 standard deviations (99.7%) of the mean when the histogram is well approx. by a normal curve
Term
 Regression Line Formula
Definition
 y=a+bx   a=(y-intercept) bx(slope)
Term
 Correlation Coefficient
Definition
 1. -1≤r≤1 2. r positive (+ trend) r negative (- trend) 3. strength close to 1 or -1 (strong) close to 0 (weak)
Term
 Double-Blind
Definition
 a test procedure in which the identity of those receiving the intervention is concealed from both the administrators and the subjects until after the test is completed
Term
 Relative Frequency
Definition
 another term for proportion; number of times event occurs divided by the number of trials (long run)
Term
 Extrapolation
Definition
 making predictions beyond intended bounds
Term
 Coefficient of Determination
Definition
 r² -Reported as a percent -measures the variation in the response variable
Term
 Frequency
Definition
 How many times the value occured in the collection of data (count)
Term
 Blind
Definition
 When someone who doesn't see the participants or doesn't participate in determining the results handles the assignment group
Term
 Random Assignment
Definition
 Assignment is left to chance (Flipping a coin)
Term
 Observational Units
Definition
 It's the individual entities whose characteristics are measured (In a study of flaws in a manufacturing system, an "observational unit" might be a toy that the system produces)
Term
 Is a mean resistant to outliers?
Definition
 No
Term
 Is a Median resistant to outliers?
Definition
 Yes
Term
 Is the standard deviation resistant to outliers?
Definition
 No
Term
 Is the (Lower Quartile-Upper Quartile) ÷ 2 resistant to outliers?
Definition
 Yes
Term
 Is the (Maximum-Minimum) ÷ 2 resistant to outliers?
Definition
 No
Supporting users have an ad free experience!