AP Stats Test- Sampling Methods and Experimental Design

You wish to survey people who have brought in their cars for service during the past month. You decide to pick a random sample of gas stations in the city and then survey all the customers who had work done during the past month. This is an example of

A bank wishes to survey its customers. The decision is made to randomly pick ten customers who just have checking accounts, ten who just have savings accounts, and ten who have both. This is an example of

A sales representative wishes to survey her client base of 47 companies. She has 47 business cards, all identical size, from her contacts in the companies. She drops them all in a small box, shakes them and picks out 5 cards for her sample. This is an example of

Two studies are run to compare the experiences of low-income families receiving food stamps to those receiving cash subsidies. The first study interviews 50 families who have been in each government program for at least 2 years, while the second assigns families to each program and interviews them after two years. Which of the following is a true statement?

Can changing diet reduce blood pressure? Vegetarian and low salt diets are both promising. Men with high blood pressure are assigned at random to four diets: normal diet, vegetarian with unrestricted salt, normal with restricted salt, and vegetarian with restricted salt. The 240 subjects are labeled 001 to 240. Software randomly assigns 60 subjects to each of the four diets. This is an example of

The Community Intervention Trial for Cessation asked whether a community wide advertising campaign would reduce smoking. The researchers located 11 pairs of communities, each pair similar in location, size, economics status, and so on. One community in each pair participated in the advertising campaign and the other did not. This is an example of

You want to take a simple random sample of 50 of the 816 students who live in a dormitory on campus. You label the students 001 to 816 in alphabetical order. In the table of random digits, you read the entries 95592 94007 69769 33547 72450 16632 81194 14873. The first three students in your sample have labels

Control groups are used in experiments in order to

You want to know the opinions of American high school teachers on the issue of establishing a national proficiency test as a prerequisite for graduation from high school. You obtain a list of high school teachers belonging to the National Education Association and mail a survey to a random sample of 2500 teachers. In all, 1347 of the teachers return the survey. Of those that responded, 32% say they favor some sort of national proficiency test. Which of the following is true?

Few people want to each discolored French fries. Potatoes are kept refrigerated before being cut into French fries to prevent spoiling and preserve flavor. Unfortunately, immediate processing of cold potatoes causes discoloring due to complex chemical reactions. The potatoes must therefore be brought to room temperature before processing. Researchers want to design an experiment in which tasters will rate the color and flavor of French fries from several groups of potatoes. The potatoes will be freshly picked, stored for a month at room temperature, or stored for a month refrigerated. They will then be sliced and cooked. Identify the experimental units, the treatment, and the response respectively

A new headache remedy was given to a group of 25 subjects who had headaches. Four hours after taking the new remedy, 20 of the subjects reported that their headaches had disappeared. From this information you conclude

A study of treatments for angina (pain due to low blood supply to the heart) compared bypass surgery, angioplasty, and use of drugs. The study looked at the medical records of thousands of angina patients whose doctors had chosen one of these treatments. If found that the average survival time of patients given drugs was the highest. What do you conclude?

Which of the following is a true statement?

A company has 1000 employees distributed throughout five assembly plants. A sample of 30 employees is to be chosen as follows. Each of the five managers will be asked to place the 200 time cards of their respective employees in a bag, shake them up, and randomly draw out six names. The six names from each plant will be put together to make up the sample. Will this method result in a simple random sample of the 1000 employees?

A town has one high school, which buses students from urban, suburban, and rural communities. Which of the following samples is recommended in studying attitudes toward tracking of students in honors, regular, and below grade level classes?