Lecture 1 Flashcards
Data, Variables, and Visualizations
What’s a descriptive statistic?
Numbers that describe a data set
what are the 3 categories of measure that makes up descriptive statistic?
1.) measures of central tendency
2.)measures of variability/spread
3.) Frequency distribution
Inferential statistic
method to make conclusions about a population using a sample
what is statistical bias?
Its when the statistic doesn’t accurately represent the population
Accuracy
is how well the the sample represents the population
Precision
is how close the samples/measurements were to each other
Define Histogram
a graph that shows the distribution of numerical data using bars
what are some things about a histogram sample that you couldn’t learn from the samples mean?
-distribution shape
- presence of outliers
- potential clusters
what happens to the difference between the mean of a sample and the mean of the population as size of the sample increase?
As the sample size increases it gets closer to the population size; meaning the difference between the mean sample and mean population size gets smaller.
Types of variables
qualitative (categorical) and quantitative (numerical)
Qualitative (categorical)
1.) nominal variables- categorical variable that describes a name, label, or category without a natural order
2.) Ordinal variable- a categorical variable where the categories have a natural order or ranking
quantitative (numerical)
Continuous variables- a variable that can take on an infinite number of values within a given range
define which variable is
country of origin
nominal
define which variable is
% of a population with a particular disease
continuous
define which variable is
Rate of breathing, recorded as low, medium, or high
Ordinal
