Sampling Distributions
Hypothesis Testing
z-tests
t-Tests
Pick that test!
100
The sampling distribution is a distribution of all the possible ______ for a certain size sample.
What are means?
100
The critical value for creating the boundaries for the rejection region are determined by the _____________.
What is the alpha level?
100
What is the Z-Score for a sample with a mean of 6 which is being compared to a sampling distribution with expected value = 9 and a standard error = 2?
What is z = -1.5?
100
Which of the following is the correct null hypothesis for a repeated-measures t test? a. MD = 0 b. µ1 = µ2 c. M1 = M2 d. µD = 0
What is µD = 0?
100
A researcher would like to examine how the chemical tryptophan, contained in foods such as turkey, can affect mental alertness. A sample of n = 9 college students is obtained and each student’s performance on a familiar video game is measured before and after eating a traditional Thanksgiving dinner including roast turkey. The average score dropped by M = 14 points after the meal with SS = 1152 for the difference scores.
What is a repeated measures t-test?
200
According to the Central Limit Theorem, the shape of the sampling distribution becomes more normally distributed as the _____ increases.
What is the sample size (or N)?
200
Concluding that a treatment has an effect when it really has no effect.
What is a Type I Error?
200
A researcher conducts a hypothesis test to evaluate the effect of an Etiquette Class on politeness. The hypothesis test produces the following results: z (65) = -2.60, p<05. Assuming that the researcher is using a two-tailed test, what is the correct conclusion? (Be specific in terms of the research question)
What is reject the null, the etiquette class does have an effect on politeness?
200
The results of a repeated measures t-test are reported as follows: t (29) = 2.70, p > .05, d = 1.69. Based on this report, how many individuals were in the sample AND should you accept or reject the null?
What is N=30 AND fail to reject the null?
200
A researcher is interested in testing the itching side effect some people reported when using new Hairy Brand Hairspray. In the general population people scratch their head approximately 2 times per hour with SD = 0.3. The researcher asks a group of women to use the new hairspray, and then records how often each woman scratches her head in an hour.
What is z-test?
300
The larger the sample size, the _______ the sampling error.
What is smaller?
300
The hypothesis that matches onto the researcher's actual hypothesis.
What is the alternate hypothesis?
300
This reports how many standard deviations above the population mean the sample mean is.
What is Cohen’s D (or Effect size)?
300
In an independent-samples hypothesis test, what does t = 0 tell us about the sample means?
What is that the two population means are equal?
300
When you are comparing two naturally occurring groups to each other.
What is an independent-samples t-test?
400
Researchers want to determine the cuteness of different breeds of puppies, rating them on a scale of 0-30. A sample of pug puppies obtained from a population with σ = 12 points has a standard error of 2 points. How many pugs are in the sample?
What is N=36?
400
When conducting a two-tailed hypothesis test, with an alpha = .01, this would be the proportion of scores which fall the rejection region on the right-hand side of the distribution.
What is p = .0050 or 0.5%
400
When this happens, you conclude that there is a significant difference between the two populations.
What is "reject the null" or "p<.05" or "test-statistic falls in the rejection region" or something similar.
400
One sample has n = 8 and SS = 21 and a second sample has n = 8 and SS = 35. What is the pooled variance for the two samples?
What is 4? (21 + 35)/(7 + 7) = 56/14 = 4
400
The test that does NOT rely on the sample size as part of it's calculation.
What is a effect-size test (or Cohen's D)?
500
In the general population, the weight of newborn babies is normally distributed with μ = 7.5lbs and σ = 1.25lbs. If you take a random sample of N = 25 newborns, what is the probability that the sample mean would be greater than M = 8lbs?
What is .0228 or 2.28% std error = 1.25/(sqrt 25) = 1.25/5 = 0.25 z = (8-7.5)/0.25 = 0.5/0.25 = 2 proportion for z = 2 is .0228
500
When you increase this in your study, the Power of your study will also go up!
What is sample size, or alpha-level.
500
A sample of 25 lifeguards from Fort Lauderdale are asked to report how many times they have seen dolphins swimming in the ocean this summer, and their mean response = 8. Researchers first compare this sample to the population of lifeguards in the US which have a mean = 6, SD = 3. Researchers also compare this sample to the population of life guards in the Dominican Republic which have a mean of 6, SD = 1. In which scenario is there a greater chance of finding a significant difference?
What is comparing Fort Lauderdale to Dominican Republic?
500
The 5 different statistics you should include when writing a conclusion for a research paper about an independent samples t-test.
What is M (for each sample), t-statistic, df, p, & d.
500
If you are comparing a sample to a population, but you only know the mean of the population (you do not know the population's SD).
What is a one-sample t-test?
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