Acquiring Data - Population & Sample
The entire group of people or items that is being studied
Population
This type of sampling involves randomly choosing a set number of people
Simple random sampling
a single set of data collected from a subject
One-variable Data
the middle number in a data set in numerical order.
Median
shows a visual summary of a set of data.
shows the minimum value, lower quartile, median, upper quartile, and range.
Box Plots
Or
Box and Whisker Plot
Any part of the population.
Sample
involves randomly choosing individuals at a fixed interval (e.g. surveying every fourth customer in the store).
Systematic Random Sampling
two sets of data collected from the same subjects
Two-variable data
the average or expected value in a data set
Mean
a number summary for a set of single variable data that includes the minimum, the maximum, the median, the first quartile and third quartile.
Five Number Summary
When an entire population is being surveyed
Census
involves dividing the population into groups and randomly selecting members from each group (e.g. dividing a population into children, teens, adults, and seniors).
Stratified Random Sampling
data that can be measured but not counted, such as time, height, and mass.
Continuous data
the data that is represented most frequently in a data set.
Mode
a chart that is usually used to observe and display relationships between two variables
Scatter Plot
A sports organization is interested in the public's opinions on the game's outcome. What would you use, a sample or a census?
Sample
involves using a method that does not randomly select a sample from a population.
Non-Random Sampling
data that is obtained by counting.
Discrete data
the middle number between the smallest number (minimum) and the median of the data set.
Lower Quartile Q1
a data point unusually far away from the general pattern
Outlier
The Canadian government would like to know how many families own a dog. Would you use a sample or a census?
Census - They will survey the entire population to determine how many families own a dog.
Identify the sampling technique.
A video game company sends a survey randomly to players who are between ages 20-30 and 30-40.
Stratified Random Sampling
Which type of data is the following:
Looking at change in amount of rainfall
over the years
Two-variable data
the difference between the upper quartile and the lower quartile. How is it calculated
Interquartile Range
IQR = Q3 - Q1
also known as a trend line, is a straight line that best represents the data on a scatter plot.
Line of Best Fit