Exercise 2.4. Calculate the relative frequencies for the frequency data shown in Figure 2.5. What percentage of patients were "very dissatisfied" with their care? Exercise 2.5. In a study comparing two treatments for a whiplash injury, one group of patients received the usual emergency department carc (normal consultation plus an advice leaflet) and the other group received "active management" care (normal consultation plus additional help). IWelve months after the initial contact, the patients were asked to rate the benefits they felt from their treatment. The results are shown in Figure 2.6 for each group (the group with missing values has been omitted). What percentage of patients felt "Much better" in each group? What percentage felt "Much worse"? How do you think that the missing values might affect thc reliability of results in general?