Standard: 7.SP.B4 – Use measures of center and measures of variability for numerical data from random samples to draw informal comparative inferences about two populations. For example, decide whether the words in a chapter of a seventh-grade science book are generally longer than the words in a chapter of a fourth-grade science book.
Grade level: Grade 7
Subject: Mathematics
Domain: Statistics & Probability
Teacher Overview
This standard focuses on using statistical measures to compare two populations. It is important because it helps students develop the ability to make data-driven decisions and understand variability within data sets. Students should have a solid grasp of basic statistical concepts such as mean, median, mode, and range. They should also understand how samples can represent populations.
After mastering this standard, students will be able to perform more complex statistical analyses and make more formal inferences and predictions based on data.
Common Misconception 1
One common misconception is that measures of center alone can provide a complete picture of the data. This is incorrect because measures of center do not account for the spread or variability within the data.
Intervention 1
Use visual aids like box plots and histograms to show how measures of variability provide additional context to measures of center.
Common Misconception 2
Another misconception is that larger samples always lead to more accurate inferences. While larger samples can be more reliable, the key is that the samples must be random.
Intervention 2
Conduct classroom activities that involve taking multiple random samples from the same population to show how sample size and randomness affect the results.
Prerequisite Knowledge
Students should understand basic statistical concepts such as mean, median, mode, and range. They should also be familiar with the concept of a sample and how it can represent a population.
Subsequent Knowledge
Students will develop skills in more advanced statistical analysis, including understanding and interpreting box plots, histograms, and other data representations. They will also learn to make more formal inferences and predictions based on statistical data.
Instructional Activities
- Conducting surveys and analyzing the data
- Creating and interpreting box plots
- Comparing data sets using measures of center and variability
- Engaging in group discussions to draw inferences from data

