A manufacturer of "Keep It Warm" bags is interested in comparing the heat retention of bags when used at five different temperatures (100°F, 125°F, 150°F, 175°F, and 200°F). Thirty bags are selected randomly from last week's production and randomly assigned, six each, to five different groups. Items from group 1 at beginning temperature 100°F were kept in bags for an hour, and the temperatures of those items were recorded after an hour. Similarly, groups 2 to 5 were assigned items at 125°F, 150°F, 175°F, and 200°F, respectively.
a Identify the type of study used here.
b What type of inference is possible from this study?