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35 Cards in this Set
 Front
 Back
A national fitness chain is considering opening a new fitness club in Eureka, California. They contact a marketing research firm to help them determine if adults in Eureka would be interested in joining such a club. From a list of all residential addresses in Eureka, the firm selects a simple random sample of 100 and mails a brief questionnaire to each. The chance that all 100 homes that just so happen to be on 2nd Avenue in Eureka end up being the sample of residential addresses selected is…

A. the same as for any other set of 100 residential addresses.
B. exactly 0. Simple random samples will spread out the addresses selected. C. reasonably large due to the “cluster” effect. D. 100 divided by the size of the population of Eureka. 

Researchers wish to determine if a new experimental medication will reduce the symptoms of allergy sufferers without the sideeffect of drowsiness.
To investigate this question, the researchers give the new medication to 50 adult volunteers who suffer from allergies. Fortyfour of these volunteers report a significant reduction in their allergy symptoms without any drowsiness. This study could be improved by A. including some people who do not suffer from allergies. B. repeating the study with only the 44 volunteers who reported a significant reduction in their allergy symptoms without any drowsiness, and giving them a higher dosage this time. C. using a control group. D. giving everyone tissues for their allergies 
Using a control group.


I collect a random sample of size n from a population and from the data collected compute a 95% confidence interval for the mean of the population. Which of the following would produce a new confidence interval with larger width (larger margin of error) based on these same data?

A. Use a larger confidence level.
B. Use a smaller confidence level. C. Compute the same interval many times. Approximately 5% of these intervals will be larger. D. A confidence interval that is being a little too overconfident. 

In formulating hypotheses for a statistical test of significance, the null hypothesis is often…
A. a statement of “no effect” or “no difference.” B. the probability of observing the data you actually obtained. C. a statement that the data are all 0. D. 0.05. 
A statement os "no effect" or "no difference."


A certain population follows a normal distribution with mean µ and standard deviation σ = 1.2. You construct a 95% confidence interval for µ and find it to be 1.1 ± 0.8. Which of the following is true?

A test of the hypotheses H0: µ = 1.2, Ha: µ ≠ 1.2 would be rejected at the 0.05 level.
A test of the hypotheses H0: µ = 1.1, Ha: µ ≠ 1.1 would be rejected at the 0.05 level. A test of the hypotheses H0: µ = 0, Ha: µ ≠ 0 would be rejected at the 0.05 level. None of these can be computed without complex math. 

The value in the population that we are trying to estimate is called a ____

parameter.


With_________ we want to generalize outside of our sample to the whole population

statistical inference


In order to use ____ ____,we have to use information from our sample to estimate the value in the population.

statistical inference


2 approaches to statistical inference are ___ and ___.

confidence intervals and significance tests


___ ____estimate the value of a population parameter.

confidence intervals


___ ____see if a claim about a population is likely to be true.

significance tests


both confidence intervals and significance tests are based on___distributions.

sampling distributions


the "twisted logic" of significance tests is:

Do the data give evidence against the claim?


to calculate a "change score," calculate the difference _______.

(After value minus Before value).


The logic of significance tests is a little backwards:__________

We state a claim and then try to see if the data find evidence AGAINST it. Or, more specifically, we are trying to see if the results or evidence goes against (contradicts) the null hypothesis.


the null hypothesis is OFTEN a statement of ___effect.

no


The null hypothesis is in contrast to the statement we want to make, or the _____ _____.

alternative hypothesis


The ____hypothesis is also abbreviated H sub 0.

null hypothesis


The "alternative hypothesis" is abbreviated ____, and sometimes ____.

H sub A; H sub 1.


In a ____tailed test, your claim is that the mean is less than 0, or your claim is that the mean is greater than 0.

1tailed test


If we do not know the direction of change, we need to take a ___test.

2tailed test


If we REJECT the null hypothesis, given our data, we can say that the data SUPPORT the ____ _____.

If we the null hypothesis, given our data, we can say that the data support the alternative hypothesis.


the________
compares the difference between 2 means 
"onesample ztest" compares the difference between 2 means.


the formula for z is _____.

z=(xbar minus mean) divided by (standard deviation divided by square root of n).
(z=x barmean/sigma/square root of n). 

In a ____tailed test, your claim is that the mean is not equal to 0.

2tailed test


Use sample mean to estimate ____________.

population mean.


This is the probability that the interval will capture the population parameter

Confidence Level


The formula for a confidence interval is this:

CI=x bar +/ (standard deviation/square root of n)(z*)


_____ is the % of curve around the mean

z star (z*)


90%: z* = _____
95%: z* = ____ 99%: z* =____ 
1.645
1.960 2.576 

SEM=_____________

standard deviation/square root of n


____variables are very similar to lurking variables.

confouding variables


______ ______ sampling is
One type of probability sampling Everyone has an equal chance of being selected In order to use___ _____sampling, use identifying information and randomly select them Usually based on random number generator 
Simple Random Sampling


Give some examples of variables we would use for Stratified Random Sampling

Examples: gender, age group, ethnicity


Name and explain some survey problems:

Undercoverage
Some groups left out of the process of choosing a sample Nonresponse Members of a population refuse to participate or cannot be contacted Response bias Participants lie, or might be affected by researcher or questions Wording of questions and question order The way you word a question may bias results The way you offer answers may bias results The order of questions may bias results Cultural factors Psychometric issues (reliability and validity) 