Practise setting up statistical studies by distinguishing populations from samples and framing investigative questions that identify the target context and parameter.
A trainer has two weight lifting classes, Class I and Class II. Each class has 9 amateur adult males and 1 professional adult male. Their body weights and number of bench press reps with 225 pounds are shown in the following dotplots. The professionals are designated as A and B.
Determine the population for a valid investigative question.
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.