a. Reporting the number of observations.

Pretty straightforward, right? All we want students to do here is report the number of observations. No crazy formulas. No intense calculations. This one's about straight-up counting, whether it's counting the number of values in a table, the number of dots on a dot plot, or adding up the frequencies in a histogram.

Of course, this also means we expect students to know when reporting the number of observations is quite simply not an option. For example, box plots and relative frequency histograms won't always give students enough information to find the number of observations—and anyone who says differently is selling something.