Content-specific conceptual understandings
Measures of central tendency (mean, median, and mode). Estimation of the mean from grouped data.
Calculation of mean using formula and technology.
Students should use mid-interval values to estimate the mean of grouped data.
For equal class intervals only.
Measures of dispersion (interquartile range, standard deviation, and variance).
Calculation of standard deviation and variance of the sample using only technology, however, hand calculations may enhance understanding. Variance is the square of the standard deviation.
Effect of constant changes on the original data.
Examples: If three is subtracted from the data items, then the mean is decreased by three, but the standard deviation is unchanged.
If all the data items are doubled, the mean is doubled and the standard deviation is also doubled.
Quartiles of discrete data.
Using technology. Awareness that different methods for finding quartiles exist and therefore the values obtained using technology and by hand may differ.
The mode, median and mean