Learn on PengiBig Ideas Math, Course 1Chapter 9: Statistical Measures

Lesson 1: Introduction to Statistics

In this Grade 6 lesson from Big Ideas Math, Course 1, Chapter 9, students are introduced to statistics by learning to distinguish between statistical and non-statistical questions, understanding that statistical questions anticipate variability in answers. Students also practice collecting and displaying numerical data using dot plots, and learn to identify clusters, peaks, gaps, and outliers within a data set.

Section 1

Recognizing Statistical Questions

Property

Statistics is the science of collecting, organizing, analyzing, and interpreting data.
A statistical question is one that anticipates variability in the data and can be answered by collecting data that varies from one individual to another.
Non-statistical questions have a single, definitive answer.

Examples

Section 2

Dot Plots

Property

An easy graph to make for numerical data is called a dot plot.
To create a dot plot, first draw a number line and then place a dot above the number line at the location of each data value.
If a value is repeated, this is represented by placing another dot above the previous instance(s) of that value.
This type of graph allows us to identify clusters (data points together in a group), gaps (intervals without any reported values), peaks (data where there are more responses than for nearby values), and outliers (values that are significantly different from the rest of the data).

Examples

  • A group of friends records the number of pets they own: 1, 0, 2, 1, 1, 3, 5. A dot plot would show a peak at 1, a cluster from 0-3, and a gap before the value at 5.
  • Students' quiz scores are: 8, 9, 10, 7, 9, 9, 8. The dot plot for this data shows a peak at 9, indicating it's the most frequent score, and all data is clustered between 7 and 10.
  • The number of goals scored in 7 soccer games was: 2, 3, 0, 1, 3, 2, 3. The dot plot has a peak at 3, showing it was the most common number of goals scored in a game.

Explanation

Dot plots are perfect for smaller sets of data. They let you see every single data point at a glance, making it easy to spot where data clumps together (clusters) or where the most common value is (peak).

Lesson overview

Expand to review the lesson summary and core properties.

Expand

Section 1

Recognizing Statistical Questions

Property

Statistics is the science of collecting, organizing, analyzing, and interpreting data.
A statistical question is one that anticipates variability in the data and can be answered by collecting data that varies from one individual to another.
Non-statistical questions have a single, definitive answer.

Examples

Section 2

Dot Plots

Property

An easy graph to make for numerical data is called a dot plot.
To create a dot plot, first draw a number line and then place a dot above the number line at the location of each data value.
If a value is repeated, this is represented by placing another dot above the previous instance(s) of that value.
This type of graph allows us to identify clusters (data points together in a group), gaps (intervals without any reported values), peaks (data where there are more responses than for nearby values), and outliers (values that are significantly different from the rest of the data).

Examples

  • A group of friends records the number of pets they own: 1, 0, 2, 1, 1, 3, 5. A dot plot would show a peak at 1, a cluster from 0-3, and a gap before the value at 5.
  • Students' quiz scores are: 8, 9, 10, 7, 9, 9, 8. The dot plot for this data shows a peak at 9, indicating it's the most frequent score, and all data is clustered between 7 and 10.
  • The number of goals scored in 7 soccer games was: 2, 3, 0, 1, 3, 2, 3. The dot plot has a peak at 3, showing it was the most common number of goals scored in a game.

Explanation

Dot plots are perfect for smaller sets of data. They let you see every single data point at a glance, making it easy to spot where data clumps together (clusters) or where the most common value is (peak).