The four members of Skylab had their lymphocyte count per cubic millimeter measured 1 day before lift-off and measured again on their return to Earth.
(a) What is the response variable in this experiment?
(b) What is the treatment?
(c) What type of experimental design is this?
(d) Identify the experimental units.
(e) Draw a diagram similar to Figure 7 or 8 to illustrate the design.