Assignments and due dates for each chapter are announced in class. Typical problems include:
3-2 page 86
2 to 24, even numbered problems
Do not calculate the mode or the midrange since we will not use either of these measures.
3-3 page 104
2 to 24, even numbered problems
Do not use formulas 3-4 or 3-5 (page 94) to compute the standard deviation. Use STATDISK or a calculator's built-in functions or a spreadsheet's built-in functions to compute the standard deviation.
3-4 page 116
2 to 14, even numbered problems
3-5 page 126
2 to 12, even numbered problems
The most important measure of variation or spread of the data is
the standard deviation. Range and quartiles are sometimes important in descriptive statistics.
The range captures 100% of the data but depends only on the minimum value and the maximum value. Primarily because the range does not take into account all the data in between the minimum and maximum values, another measure of variation is required.
Because the standard deviation uses all data in the sample or population, the standard deviation is far more useful.
The Empirical Rule for Bell-Shaped distributions (page 100) approximates the amount of data in several important intervals of the distribution. Because we can infer how much of a distribution is in important intervals, the Empircal Rule is one of the cornerstones of statistics.