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Misc.
Sampling Method
BIASES
Experimental Design & 2 Randoms
More about Experimental design + 1 more rando's
PROBABILITY
100

How to identify outliers for univariate data

What is Q1 - 1.5(IQR) and Q3 + 1.5(IQR)?

100
"A sales representative wishes to survey her client base of 47 companies. She has 47 business cards, all of the identical size, from her contacts in the companies, from her contacts in the companies, and decides to drop them all in a small box, shake them up, and reach in to pick 5 cards for her sample" is an example of this kind of sampling method.
Simple Random
100
What is bias in conducting surveys? A. An example of sampling error. B. Lack of control group. C. Confounding variables. D. Difficulty in concluding cause and effect. E. A tendency to favor the selection of certain members of a population.
E. A tendency to favor the selection of certain members of a population.
100
A critical difference between experiments and observational studies is A. an experiment often suggests a causal relationship, whereas an observational study only suggests an association. B. observation studies make use of randomization, whereas experiments do not. C. experiments are generally more cost and time effective than observational studies. D. tests of significance can be used on data collected from experiments but not on data from observational studies. E. experiments are free to choose subjects from an entire population, whereas an observational study only considers a random sample.
A. an experiment often suggests a causal relationship, whereas an observational study only suggests an association.
100
Which of the following best explains why we try to guard against confounding when designing experiments? A. Confounding can lead to bias. B. Confounding can conflict with randomization. C. Confounding can lead to uncertainty as to which variable is causing an effect. D. Confounding can make it more difficult to separate subjects into treatment and control groups. E. Confounding can negate the benefits of blinding.
C. Confounding can lead to uncertainty as to which variable is causing an effect.
100

The rule for finding the probability of rolling a fair die three times and getting three fours.

What is P(rolling three 4s) = P(4)*P(4)*P(4) = P(4)^3?

200

Events that have no outcomes in common and can never occur simultaneously, for which the addition rule is used.

What are disjoint events (or mutually exclusive events)?

200
"A company wishes to survey what people think about a new product it plans to market. They decide to randomly sample from their customer database as this includes phone numbers and addresses" is an example of this kind of sampling method.
What is convenience sampling?
200
"Many people believe this playground is too small and in need of repair. Do you think the playground should be repaired and expanded even if that means raising the entrance fee to the park?" is an example of this kind of bias.
What is response bias? Bonus points, if you can describe how it creates bias.
200
Before taking an exam, students either went to bed at their normal times or were sleep deprived 4 or 8 hours. Half of each group were given a caffeine pill before taking the exam. Determine the number of factors, levels for each, and number of treatments.
Two factors, one with two and one with three levels, six treatments.
200
An advantage to using surveys as opposed to experiments is that. A. surveys are generally cheaper to conduct. B. it is generally easier to conclude cause and effect from surveys. C. surveys are generally not subject to bias. D. surveys involve use of randomization. E. surveys can make sure of stratification.
A. surveys are generally cheaper to conduct
200

The rule for finding the probability of a female given that they are an AP Stats student.

What is P(Female|AP Stats Student) = P(Female AP Stats Student)/P(AP Stats Student)

300

This type of random variable requires a fixed number of trials.

What is a binomial random variable?

300
A human resources department plans to survey 100 of the 3,000 employees in the firm. An alphabetical list of the employees is available, a random number between 1 and 30 is picked, and the sample consists of the person that far down the list together with every 30th person after that. This procedure is an example of which type of sampling? A. Cluster B. Convenience C. Simple Random D. Stratified E. Systematic
E. Systematic
300
A news paper advice columnist asks her readers if they would have married their current souse if they had it to do over again. Of the 25,000 or so responses, 80% said no. What does this show?
The survey is meaningless because of voluntary response bias.
300

The type of significance test used for the mean of a single population when the standard deviation of the population is unknown.

What is a T test (or T procedure)?

300
In a study of Parkinson's disease, 100 volunteers had incisions made through their skulls. The patients were randomly sorted into two groups, one of which had a new drug inserted into the brain. In the other group, the skulls were closed with no treatment given. The patients did not know who received the drug. In the weeks to follow all 100 volunteers showed similar improvement in physical condition. What is this an example of?
The placebo effect
300

The rule for finding the probability of obtaining the first success on the 5th trial.

What is P(X=5) = p(1-p)^4

400

This calculator command can be used to find the area under a normal distribution and above an interval.

What is normalcdf?

400

To conduct a survey on holiday shopping patterns, a researcher opens a telephone book to a random page, closes his eyes, puts his finger down on the page, and then reads off the next 100 names. This is an example of...

Systematic sample.

400
Which of the following statements is incorrect? A. Voluntary response samples often underrepresent people with strong opinions. B. Convenience samples often lead to undercoverage bias. C. Questionnaires with nonneutral wording are likely to have response bias. D. There is no way to fix the results if a biased sampling method was employed. E. Nonresponse bias should be avoided because those who do not respond might have different views from those who do respond.
A. Voluntary response samples often underrepresent people with strong opinions.
400

This phrase is used to describe an observed effect so large that it would rarely occur by chance.

What is statistically significant?

400

This experimental design involves the random assignment of units to treatments which are carried out separately within each group of units known to be similar in some way that is expected to affect the responses.

What is block design?

400

The rule for finding 10 successes in 15 trials.

What is P(X=10) = (15 C 10)*p^10*(1-p)^5

500

Applying a logarithmic transformation to both variables causes this type of model to become linear.

What is a power model?

500
A candy manufacturer wants to test consistency of the sugar content of chocolate-covered cherries produced in one factory. The company decides to randomly select three boxes of chocolate-covered cherries from each day's production run at the factory and analyze every cherry in each of these boxes as to sugar content. What type of sampling is this? A. Cluster B. Convenience C. Simple random D. Stratified E. Systematic
A. Cluster
500
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...
Voluntary response bias
500

50 migraine patients are randomly selected from hospital records. Half the patients are told to drink ice water and sit in the dark when they next experience a migraine; the remaining patients are told to use neither of these possible remedies. Participants then report back as to relief, if any. Faults of this experimental design include all of the following except: A. Lack of randomization B. Confounding variables C. Lack of blinding D. Unclear factor levels E. Measurement of response variable

C. Lack of blinding

500

3 Part Question for 1,000 pts..

1) This measure of center is more resistant to outliers than the mean.

2) To calculate, subtract the mean of the distribution from the observed x, then divide by the standard deviation.

3) This rule helps to determine if data is normally distributed by checking the number of observations within each interval.

1) What is the median?

2) What is the z-score (or standardized value)?

3) What is the 68-95-99.7 rule?

500

3 Part Question for 1,000 pts..

1) The population is divided into groups. Some groups are randomly selected and all individuals in the chosen groups are sampled.

2) When some groups in the population are left out of the process of choosing a sample

3) The effects of two variables on the response cannot be distinguished from each other.


1)What is cluster sampling?

2) What is undercoverage?

3) What is confounding?