In this unit, students use their knowledge of analyzing data to discover the importance of using random sampling in order to obtain a sample that is representative of the larger population. Students will learn that in order to make valid inferences about the larger population, they must obtain a representative sample. Students will develop an understanding of how to use measures of center and variability found in their sample to make inferences about the larger population and to compare populations.
Key Concepts:
 We can draw inferences about a population from a sample only if the sample is representative of the population.
 Randomness of sampling is essential to making inferences.
 We can compare the measures of center and variability to make comparative inferences about two populations.
Prior Knowledge Needed:
 Understanding data distributions; (Grade 6, Unit 12, 6.SP.A.1, 6.SP.A.2, 6.SP.A.3)
 Analyzing data; (Grade 6, Unit 13, 6.SP.B.4, 6.SP.B.5)
 Finding probability of simple events; (Grade 7, Unit 8, 7.SP.C.5, 7.SP.C.6, 7.SP.C.7, 7.RP.A.3)
 Finding probability of compound events; (Grade 7, Unit 9, 7.SP.C.8, 7.RP.A.3)
Units on the Horizon:
 Patterns of association in bivariate data; (Grade 8, Unit 8)
Lessons

Lesson objective: Understand that randomness of sampling is essential to making inferences. Students bring prior knowledge of summarizing numerical data sets in relation to their context, such as by describing the nature of the attribute under investiga...

Lesson objective: Acquire random samples and be aware of biases. Students bring prior knowledge of summarizing numerical data sets in relation to their context, such as by describing the nature of the attribute under investigation, including how it is m...

Lesson objective: Develop a method for acquiring a random sample. Students bring prior knowledge of summarizing numerical data sets in relation to their context, such as by: Describing the nature of the attribute under investigation, including how it is...

Lesson objective: Understand that inferences about a population can be drawn only from representative samples. Students bring prior knowledge of relating the choice of measures of center and variability to the shape of the data distribution and the cont...

Lesson objective: Make inferences based on representative samples. Students bring prior knowledge of relating the choice of measures of center and variability to the shape of the data distribution and the context in which the data were gathered from 6.S...

Lesson objective: Apply proportional reasoning to hypothesize about the greater population. Students bring prior knowledge of relating the choice of measures of center and variability to the shape of the data distribution and the context in which the da...

Lesson objective: Compare the measures of center and variability to make inferences about two populations. Students bring prior knowledge of displaying numerical data in plots on a number line, including dot plots, histograms, and box plots from 6.SP.B....

Lesson objective: Compare two populations using the mean and mean absolute deviation (MAD). Students bring prior knowledge of displaying numerical data in plots on a number line, including dot plots, histograms, and box plots from 6.SP.B.4. This prior k...

Lesson objective: Compare two populations using the median and interquartile range (IQR). Students bring prior knowledge of displaying numerical data in plots on a number line, including dot plots, histograms, and box plots from 6.SP.B.4. This prior kno...

Lesson objective: Draw informal comparative inferences about two populations based on measures of center and variability. Students bring prior knowledge of displaying numerical data in plots on a number line, including dot plots, histograms, and box plo...