Lesson 2Statistical Questions
Let's look more closely at data and thequestions they can help to answer.
2.1 Pencils on A Plot
2.2 Whats in the Data?
Ten sixth-grade students at a school were each asked five survey questions. Their answers to each question are shown here.datasetA0113000211datasetB12121212121212121212datasetC6576453468datasetD6666666666datasetE3791164216610
2.3 What Makes a Statistical Question?
These three questions are examples of statistical questions:
These three questions are not examples of statistical questions:
2.4 Sifting for Statistical Questions
Are you ready for more?
Tyler and Han are discussing the question,Which sixth-grade student lives the farthest from school?
Do you agree with either one of them? Explain your reasoning.
Lesson 2 Summary
We often collect data toanswer questionsabout something. The data we collect may showvariability, which means the data values are not all the same.
Some data sets have more variability than others. Here are two sets of figures.
Set A has more figures with the same shape,color, or size. Set B shows more figures withdifferent shapes, colors, or sizes, so set B hasgreater variability than set A.
Both numerical and categorical data can show variability. Numerical sets can contain different numbers, and categorical sets can contain different categories or types.
When a question can only be answered byusing data and we expect thatdata tohave variability, we call it astatistical question. Here are some examples.
To answer the question about books, we may need tocount all of the books in each classroom of aschool. The data we collect would likelyshow variabilitybecausewe would expect each classroom to have a different number of books.
In contrast, the question How many books are in your classroom?isnota statistical question. If we collect data to answer the question (for example, by asking everyone in the class to count books), the data can be expected to show the same value. Likewise, if we ask all of the students at a school where they go to school, that question is not a statistical question because the responseswill all be the same.
A statistical question can be answered by collecting data that has variability.Here are some examples of statistical questions:
Variability meanshaving different values.
For example, data set B has more variability than data set A. Data set B has many different values, while data set A has more of the same values.
Lesson 2 Practice Problems