NASA experiment. A NASA study compared two methods of determining white blood cell counts in laboratory animals. Table 11.5 lists results for 42 paired observations. Calculate DELTA values for each observation and plot these differences as a stemplot. Based on this plot, do you think the methods are interchangeable?
TABLE 11.5 Data for Exercise 11.27. White blood cells counts (×1000 dL) by Celdyne method and Unopett method, n = 42.

Source: Data from student Adam Seddiqi. Data stored online in the file SEDDIQ.SAV.