Calculating Mean Absolute Deviation (MAD)
Calculating Mean Absolute Deviation (MAD) and Interquartile Range (IQR) are Grade 7 statistics measures covered in Big Ideas Math Advanced 2, Chapter 15: Probability and Statistics. MAD equals the sum of absolute deviations from the mean divided by n, and measures spread for symmetric distributions. IQR equals Q3 minus Q1 and measures the spread of the middle 50% of data, making it resistant to outliers.
Key Concepts
Mean Absolute Deviation (MAD): $MAD = \frac{\text{sum of absolute deviations from mean}}{n}$.
Interquartile Range (IQR): $IQR = Q 3 Q 1$.
Common Questions
What is Mean Absolute Deviation (MAD)?
MAD measures how spread out data values are from the mean by averaging the absolute distances from each data point to the mean. A larger MAD indicates more variability in the dataset.
How do you calculate MAD?
Find the mean, calculate the absolute difference between each data value and the mean, sum all those absolute differences, then divide by the number of data points.
What is the difference between MAD and IQR?
MAD uses all data points and is used with symmetric distributions, while IQR measures the spread of only the middle 50% of data and is resistant to outliers, making it better for skewed distributions.
What textbook covers MAD and IQR in Grade 7?
Big Ideas Math Advanced 2, Chapter 15: Probability and Statistics covers both Mean Absolute Deviation and Interquartile Range as measures of variability.