Normal Distribution
What is a normal distribution?
A symmetric, bell-shaped distribution.
What are the key components of describing a distribution?
Shapes, outlier, center, spread
Adding 10 to every value affects which measures of center?
Mean and Median
What numbers are included in the five number summary?
Minimum, Q1, Median, Q3, and Maximum
Eye color is what type of data?
Categorical data.
What is the mean?
The mean is the average of all data points.
What is a unimodal?
A graph that has one peak.
What doesn’t double when you multiply all data values by 2?
Shape of distribution, z-scores and variance
What is the range between Q1 and Q3?
The IQR.
Height measured in inches is an example of what type of data?
Quantitative data
What is standard deviation?
Standard deviation is a value that tells you how spread out the numbers in the data set are from the mean.
What is bimodal?
A graph that has two peaks.
Adding a constant to every value changes everything except the…
Standard Deviation
How do you find the range in a data set?
You subtract the maximum and minimum
What type of graphs can be used for quantitative data?
Dot-plots, histograms, box plots and steam-and-leaf plots
How do you interpret a positive z-score or a negative z-score?
A ________ of ________ is ____ standard deviations above the mean
A ________ of ________ is ____ standard deviations below the mean
What happens if too much data on the graph is positive values?
The data becomes skewed to the right.
What happens when you multiply every value by 5?
The standard deviation and the mean change everything else stays the same.
What is the IQR rule used for and what are the formulas?
The IQR rule is used for outliers.
Q1-1.5(IQR) for low outliers
Q3+1.5(IQR) for high outliers
What type of graphs are used for categorical data?
Mosaic plots, side-by-side graph, and segmented bar graph
What is the empirical rule?
The empirical rule dictates how data clusters around the mean in a perfectly normal distribution.
What types of graphs can be used for quantitative data?
Histograms, dotplots, stemplots, and boxplots.
Compare the effects of adding a constant to all values versus multiplying all values by a constant.
Adding a number moves all the data up or down. Multiplying by a number stretches or shrinks the data.
How do you get the five number summary on a calculator?
Stat -> #1 -> edit (enter data) -> Stat -> calc -> #1: one variable stats -> calculate -> enter -> scroll to the bottom for the five number summary
What is a discret variable?
A variable that can only take specific countable values, such as the number of students in a class.