Sampling & Studies
A sample where every person has an equal chance of being selected.
What is a random sample?
The middle value of an ordered data set.
What is the median?
The difference between the maximum and minimum values.
What is the range?
The slope of a horizontal line.
What is 0?
A number between −1 and 1 that measures the strength of a linear relationship.
What is the correlation coefficient?
The horizontal axis on a graph.
What is the x-axis?
Selecting every 5th customer entering a store is this type of sampling.
What is systematic sampling?
The value that appears most often in a data set.
What is the mode?
A distribution with tall bars in the middle and short bars on the ends is called this.
What is normal (bell-shaped)?
The equation of a vertical line where all x values are 4.
What is x = 4?
The data points have this type of correlation if r = 1.
What is perfect positive correlation?
The point where the x-axis and y-axis meet.
What is the origin?
A type of study that collects data from people about events that already happened.
What is a retrospective study?
The mean of 4, 6, 8, 12.
What is 7.5?
A distribution with shorter bars on the right and taller bars on the left is called this.
What is skewed to the right?
The slope between the points (2, 5) and (6, 13).
What is 2?
True or False: If r = 0.3, is the linear correlation considered strong.
What is false?
A line with negative slope moves in this direction as you move to the right.
What is down?
A type of sample in which researchers divide students into freshmen, sophomores, juniors, and seniors and randomly select some from each group.
What is stratified sampling?
The median of: 2, 5, 7, 10, 13, 20.
What is 8.5?
According to the 68-95-99.7 Rule, this percent of values fall within 2 standard deviations of the mean.
What is 95%?
The equation of the line with slope 3 and y-intercept −2.
What is y = 3x − 2?
The line that best fits the data in a scatterplot is called this.
What is the least squares regression line?
A histogram uses these to show frequencies.
What are bars?
A statistical mistake in which a study claims that eating ice cream causes sunburn because both increase during summer.
What is confusing correlation with causation?
The measure of center that is best to use when a data set contains one extremely large outlier.
What is the median?
A box-and-whisker plot is built from these five numbers.
What are the minimum, Q1, Q2, Q3, and maximum?
The equation of a line in slope-intercept form that passes through (1, 4) and (5, 12).
What is y = 2x + 2?
True or False: Correlation always means one variable causes the other.
What is False?
The type of issue that occurs if a researcher uses only volunteers from social media to conduct a survey.
What is voluntary response bias?