In Topics B and C, students study quantitative ways to summarize numerical data sets in relation to their context and to the shape of the distribution. The mean and mean absolute deviation (MAD) are used for data distributions that are approximately symmetric, and the median and interquartile range (IQR) are used for distributions that are skewed. Students apply their experience in writing, reading, and evaluating expressions in which letters stand for numbers (6.EE.A.2) as they learn to compute and interpret two pairs of statistical measures for center and spread (6.SP.A.5).
In Topic B, students study mean as a measure of center and mean absolute deviation as a measure of variability. Students learn that these measures are preferred when the shape of the distribution is roughly symmetric.