Construct ungrouped and grouped frequency distributions
Recognize that real limits of values can be based on whole numbers or on decimals depending on the degree of accuracy to which the values are reported.
In a grouped frequency distribution, identify the following:
In a frequency distribution, calculate:
Define cf and c%
Draw bar graphs, histograms, frequency polygons, and cumulative graphs; explain how and where points (or bars) are plotted in each one.
For each type of graph, identify (a) the type of data for which it is appropriate, and (b) the type of information conveyed.
Be able to read, from a cumulative graph, the percentage of scores falling below any score point or the score point below which any given percentage falls.
Define percentile and percentile rank. Given a percentile or percentile rank, be able to interpret it (e.g., Tell what "John fell at the 30th percentile" means).
Read percentiles and percentile ranks from a c% graph.
Recognize various types of symmetrical and nonsymmetrical distribution, and distinguish between examples of:
Recognize interpretations of skewed distributions (e.g., whether a distribution of test scores indicates a relatively easy or relatively hard test).
Define deciles and quartiles, and be able to convert percentiles, deciles, and quartiles into one another.
Be able to use the differences between X25 (Q1), X50 (Q2), and X75 (Q3) to decide on the symmetry or skew (including direction of skew) of a distribution.