AP Stats Review Questions II

A television station is interested in predicting whether voters in its viewing area are in favor of federal funding for health care. It asks its viewers to phone in and indicate whether they support or are opposed to this. Of the 2241 viewers who phoned in, 1574 were opposed to federal funding for healthcare.
Referring to the information above, the viewers who phoned in are

• a voluntary response sample
• a convenience sample
• a census
• a population

A marketing research firm wished to determine if the adult men in Laramie, Wyoming, would be interested in a new upscale men's clothing store. From a list of all residential addresses in Laramie, the first selects a simple random sample of 100 and mails a brief questionnaire to each. The population of interest is

• all adult men in Laramie, WY
• all residential addresses in Laramie, WY
• the members of the marking firm conducting the survey
• the 100 addresses to which the survey was mailed

A researcher is interested in the cholesterol levels of adults in the city in which she lives. A free cholesterol screening program is set up in the downtown area during the lunch hour. Individuals can walk in and have their cholesterol levels determined for free. One hundred and seventy three people use the service, and their average cholesterol is 217.8. The sample obtained is an example of

• a simple random sample, since the experimenter did not know beforehand which individuals would come to the screening.
• a stratified sample of high and low cholesterol individuals
• a sample probably containing bias and undercoverage.
• a multistage sample of varying cholesterol levels.

 You are testing a new medication for relief of depression. You are going to give the new medication to subjects suffering from depression and see if their symptoms have lessened after a month. You have eight subjects available. Half of the subjects are to be given the new medication and the other half a placebo. The names of the eight subjects are given below.
1. Blumenthal  2. Costello  3. Duvall  4. Fan 
5. House  6. Long  7. Pavlicova  8. Tang
Using the list of random digits
81507 27102 56027 55892 33063 41842
81868 71035 09001 43367 49497
starting at the beginning of this list and using single-digit labels, you assign the first four subjects selected to receive the new medication, while the remainder receive the placebo. The subjects assigned to the placebo are

• Blumenthal, Costello, Duvall, and Fan.
• Blumenthal, House, Pavlicova, and Tang
• House, Long, Pavlicova, Costello, Duvall, Fan, and Long
• Costello, House, Duvall and Long

We say that the design of a study is biased if which of the following is true?

• A racial or sexual preference is suspected
• Random placebos have been used
• Certain outcomes are systematically favored
• None of the above.

You draw two marbles at random from a jar that has 20 red marbles and 30 black marbles without replacement.  What is the probability that both marbles are red?

• 0.1551
• 0.1600
• 0.2222
• 0.4444

Let the random variable X represent the weight of male black bears before they begin hibernation.  Research has shown that X is approximately Normally distributed with a mean of 250 pounds and a standard deviation of 50 pounds.  What is P(X > 325 pounds)?

• 0.0668
• 0.2514
• 0.7486
• 0.8531

Songs on Leila's smartphone have a mean length of 4.3 minutes and a standard deviation of 1.2 minutes.  The phone inserts a period of silence between songs that has a length of 0.2 minutes and a standard deviation of 0.1 minutes.  What are the mean and standard deviation of time it takes for the phone to play a randomly selected two-song sequence?

• Mean = 4.5 min.; SD = 2.5
• Mean = 8.8 min.; SD = 2.5
• Mean 4.5 min.; SD = 1.7
• Mean = 8.8 min.; SD = 1.7

The sampling distribution of a statistic is

• the probability that we obtain the statistic in repeated random samples.
• the mechanism that determines whether randomization was effective.
• the distribution of values taken by a statistic in all possible samples of the same sample size from the same population.
• the extent to which the sample results differ systematically from the truth.

Principal Rusk picks 75 students at a recent varsity football game to be used for the sample.  This is what type of sampling design?

• SRS
• Stratified
• Convenience
• Voluntary Response

Tags

CCSS.HSS.IC.B.3