1

Select one answer.

10 points

Research Question:What is the combined effect of fertilizer and watering on cherry tomato plants?

Planters were built that each contained 10 cherry tomato plants. Each planter was identical except that it received a different treatment of water and fertilizer than the other planters. Treatments consisted of a combination of one of four watering schedules and one of three fertilizer concentrations. The plants were tended according to these treatments, and after 65 days, the average number and weight of the tomatoes per plant were measured for each treatment group.

How many different groups are there altogether in this study?

1. 3
2. 4
3. 7
4. 12

Question 2

Select all that apply.

10 points

Research Question:What is the combined effect of fertilizer and watering on cherry tomato plants?

Planters were built that each contained 10 cherry tomato plants. Each planter was identical except that it received a different treatment of water and fertilizer than the other planters. Treatments consisted of a combination of one of four watering schedules and one of three fertilizer concentrations. The plants were tended according to these treatments and after 65 days the average number and weight of the tomatoes per plant were measured for each treatment group.

Which of the following is an explanatory variable in this study? Check all that apply.

1. Fertilizer schedule
2. Number of days of treatment
3. Number of plants per planter
4. Number of tomatoes per plant
5. Watering schedule

Question 3

Select one answer.

10 points

A simple random sample of 1,110 adult Americans is selected, and each person is asked the following question:

In light of the huge national deficit, should the government at this time spend additional money to establish a national system of health insurance?

Only 39% of respondents answered yes. Which of the following is an appropriate conclusion about the results of this summary?

1. They probably understate the percentage of people who favor a system of national health insurance because of the questions wording.
2. They are inaccurate because of convenience sampling.
3. They are reasonably accurate because the study used a large simple random sample.
4. They probably overstate the percentage of people who favor a system of national health insurance because of the questions wording.
5. They are inaccurate because of voluntary response.

Question 4

Select one answer.

10 points

When surveying subjects about sensitive or self-incriminating topics, what technique might be used to help ensure that individuals answer sensitive or self-incriminating questions honestly?

1. Asking questions in random order
2. Using randomized response
3. Asking technically complex questions
4. Using simple, direct questions