AP Stat Test A Gathering Data

Military funding A college group is investigating student opinions about funding of the military. They phone a random sample of students at the college, asking each person one of these questions (randomly chosen): A: "Do you think that funding of the military should be increased so that the United States can better protect its citizens?" B: "Do you think that funding of the military should be increased?" Which question do you expect will elicit greater support for increased military funding?

- A will elicit greater support - use positive words like "better protect the citizens", people will feel as though they have to answer yes - this is response bias

b) State your Conclusion

- According to my simulation of 3 trials, Brian can expect to check approximateley 5.67 CDs to get five good CD's for the execultive.

A headline in a local newspaper announced "video game playing can lead to better spatial reasoning abilities." The article reported that a study found "statistically significant differences" between teens who play video games and teens who do not, with teens who play video games testing better in spatial reasoning. Do you think the headline was appropriate? Explain.

- NO - you can not conclude causation from a study - only experiments can conclude causation since there is control, randomization and control - there could be something about the teens that made them good at both

Brian is a systems manager for a large company. In his work, he has found that about 5% of all CDs he orders are bad. He needs to give one of the executives at his company five good CDs. Conduct a simulation to estimate how many CDs Brian will have to check to get five good CDs for the executive. a. Describe how you will use a random number table to conduct this simulation.

- The component is checking CDs. - Assign number 00-04 to rep bad CD's - 05-99 = good CD's - read the random digit table 2 digits at a time from left to right - ignore repeated numbers and numbers other than 00-99 - when 5 Good CDs have been selected, end the trial - repeat 3 times for 3 trials

A consumer group wants to see if a new education program will improve the spending habits of college students. Students in an economics class are randomly assigned to three different courses on spending habits. a. What are the experimental units? b. How many factors are there? c. How many treatments are there? d. What is the response variable?

a) Students in economics class b) 1 c) 3 d) spending habits

Which of the following is NOT required in an experimental design? a. blocking b. control c. randomization d. replication e. all are required in an experimental design

a. blocking

A basketball player has a 70% free throw percentage. Which plan could be used to simulate the number of free throws she will make in her next five free throw attempts? I. Let 0,1 represent making the first shot and 2,3 represent making the second shot.....8,9 represent making the fifth shot. Generate five random numbers 0-9 ignoring repeats II. Let 0,1,2 represent missing a shot and 3,4....,9 represent making a shot. Generate five random numbers 0-9 and count how many numbers are in 3-9 III. Let 0,1,2 represent missing a shot and 3,4....,9 represent making a shot. Generate five random numbers 0-9 and count how many numbers are in 3-9, ignoring repeats a. I only b. II only c. III only d. II and III e I, II, and III

b. II only

A researcher wants to compare the effect of a new type of shampoo on hair condition. The researcher believes that men and women may react differently to the shampoo. Additionally, the researcher believes that the shampoo will react differently on hair that is dyed. The subjects are split into four groups: men who dye their hair; men who do not dye their hair; women who dye their hair; women who do not dye their hair. Subjects in each group are randomly assigned to the new shampoo and the old shampoo. This experiment a. is completely randomized b. has three factors (shampoo type, gender, whether hair is dyed) c. has two factors (shampoo type and whether hair is dyed) blocked by gender d. has two factors (gender and whether hair is dyed) blocked by shampoo type e. has one factor (shampoo type), blocked by gender and whether hair is dyed

b. has three factors (shampoo type, gender, whether hair is dyed)

A company sponsoring a new Internet search engine wants to collect date on the ease of using it. Which is the best way to collect data? a. census b. sample survey c. observational study d. experiment e simulation

b. sample survey

Suppose your local school district decides to randomly test high school students for attention deficit disorder (ADD). There are there high schools in the district, each with grades 9-12. The school board pools all of the students together and randomly samples 250 students. Is this a simple random sample? a. Yes, because the students were chosen at random b. Yes, because each student is equally likely to be chosen c. Yes, because they could have chosen any 250 students from throughout the district d. No, because we can't guarantee that there are students from each school in the sample e. No, because we can't guarantee that there are students from each grade in the sample

c. Yes, because they could have chosen any 250 students from throughout the district

Placebos are a tool for a. sampling b. blocking c. blinding d. control e. randomization

c. blinding

More dogs are being diagnosed with thyroid problems than have been diagnosed in the past. A researcher identified 50 puppies without thyroid problems and kept records of their diet for several years to see if any developed thyroid problems. This is a(n) a. randomized experiment b. survey c. prospective study d. retrospective study e. blocked experiment

c. prospective study

Double-blinding in experiments is important so that I. The evaluators do not know which treatment group the participants are in II. The participants do not know which treatment group they are in III. No one knows which treatment any of the participants are getting a. I only b. II only c. III only d. I and II e. I, II, and III

d. I and II

A chemistry professor who teaches a large lecture class surveys his students who attend his class about how he can make the class more interesting, hoping he can get more students to attend. This survey method suffers from a. voluntary response bias b. nonresponse bias c. response bias d. undercoverage e. none of the above

d. undercoverage

The January 2005 Gallup Youth Survey telephone a random sample of 1,028 U.S. teens and asked these teens to name their favorite movie from 2004. NAPOLEON DYNAMITE had the highest percentage with 8% of teens ranking it as their favorite movie. Which is true? I. The population of interest is all U.S. teens II. 8% is a statistic and not the actual percentage of all U.S. teens who would rank this movie as their favorite. III. This sampling design should provide a reasonably accurate estimate of the actual percentage of all U.S. teens who would rank this movie as their favorite. a. I only b. II only c. III only d. I and II e. I, II, and III

e. I, II, and III