Data
This measure of center is found by summing all values and dividing by the number of observations. Example: If the data are 5, 10, and 15, this is 10.
What is the mean?
This value measures the strength and direction of a linear relationship between two variables and ranges from -1 to 1
What is correlation?
This type of study observes individuals without imposing treatments.
What is an observational study?
The middle value in an ordered data set, which splits the data into two equal parts.
what is the median?
This is the difference between an observed value and the value predicted by a regression line.
Example: If observed y=10 and predicted y=8, this is 2.
What is a residual?
This term refers to the use of enough experimental units to reduce variability in the results.
Example : Your school has grades 9, 10, and 11. To get opinions on a new lunch menu, the principal picks a few students from each grade.
What is replication?
This measure of spread calculates the distance between the first quartile and third quartile.
What is the interquartile range?
This is the equation for a straight line that minimizes the sum of squared residuals: y^=a+bx
what is the least squares regression line?
In this sampling method, the population is divided into groups, and entire groups are randomly selected.
What is cluster sampling?
This formula calculates how far each data point is from the mean on average.
What is standard deviation?
This rule identifies outliers by looking at 1.5 times the IQR above Q3 or below Q1.
What is the 1.5 × IQR rule?
This sampling method splits the population into subgroups and selects a random sample from each subgroup.
What is stratified sampling?
It measures how many standard deviations a value is from the mean.
Example: If the class average on a test is 75, and you score 85, you’re above average. A z-score tells you how far above or below the average you are compared to everyone else.
What is z-score?
To describe a data set, use this mnemonic: Shape, Outliers, Center, and Spread.
What is SOCS?
When researchers actively impose treatments and control factors, the study is called this.
What is an experiment?