Practise turning study aims into answerable investigative questions that name the population, parameter, and either a group comparison or target threshold.
A horticulturist plans a study on the use of compost tea for plant disease management. She obtains 18 identical beds, each containing a random selection of five minipink rose plants. Some bed or beds will not receive compost tea. For those beds receiving compost tea, she plans to use two different composting times (2 and 5 days), two different compost preparations (aerobic and anaerobic), and two different spraying techniques (with and without adjuvants). Midway into the growing season she will check all plants for rose powdery mildew disease.
Determine a valid investigative question about infection proportions in beds using aerobic and anaerobic preparations.
Is there convincing statistical evidence that the proportion of minipink rose plants infected with rose powdery mildew differs between beds using aerobic preparations and beds using anaerobic preparations?