Identifying Outliers
Identifying outliers is a Grade 6 statistics skill in Big Ideas Math Advanced 1, Chapter 9: Statistical Measures. An outlier is a data value that is significantly higher or lower than most other values in a data set. Students learn to spot outliers visually using dot plots and box plots, and analytically using the 1.5xIQR rule.
Key Concepts
Outliers are values that are significantly different from the rest of the data. These are data points that stand far apart from the main group of values. We can identify potential outliers by looking for values that seem unusually high or low compared to the other data points in the set.
Common Questions
What is an outlier in Grade 6 statistics?
An outlier is a data value that stands apart from the rest — either much higher or much lower than the other values. For example, if most test scores are between 70 and 90 but one score is 20, the score of 20 is an outlier.
How do you identify outliers in a data set?
Look for values far from the cluster of data on a dot plot or box plot. Analytically, use the 1.5 x IQR rule: values below Q1 - 1.5*IQR or above Q3 + 1.5*IQR are outliers.
Why does identifying outliers matter?
Outliers can distort statistical measures like the mean. Identifying them helps you decide whether to include or exclude them, and whether the mean or median is a better measure of center for the data.
Where is identifying outliers taught in Big Ideas Math Advanced 1?
Identifying outliers is covered in Chapter 9: Statistical Measures of Big Ideas Math Advanced 1, the Grade 6 math textbook.