Chapter 8 Quiz
A researcher administers a treatment to a sample of participants selected form a population with μ= 80. If a hypothesis test is used to evaluate the effect of the treatment, which combination of factors is most likely to result in rejecting the null hypothesis?
A sample mean much different than 80 for a large sample
Which of the following accurately describes a hypothesis test
An inferential technique that uses the data from a sample to draw inferences about a population
What is measured by the numerator of the z-score test statistic?
The actual distance between M and μ
What is measured by the denominator of the z-score test statistic?
The average distance between M and μ that would be expected of H0 was true
A researcher selects a sample and administers a treatment to the individuals in the sample. If the sample is used for a hypothesis test, what does the alternative hypothesis (H1) say about the treatment?
The treatment causes a change in the scores
A researcher selects a sample and administers a treatment to the individual in the sample. If the sample is used for a hypothesis test, what does the null hypothesis (H0) say about the treatment?
The treatment has no effect on the scores
A researcher administers a treatment to a sample of participants selected from a population with μ= 80. If the researcher obtain a sample mean of M= 88, which combination of factors is most likely to result in rejecting the null hypothesis?
σ= 5 and a= .05
A researcher administers a treatment to a sample of participants selected form a population with μ= 80. If the researcher obtains a sample mean of M= 88, which combination of factors is most likely to result in rejecting the null hypothesis?
σ= 5 and n= 50
The critical boundaries for a hypothesis test are z= +/- 1.96. If the z-score for the sample data is z= -1.90, what is the correct statistical decision?
Fail to reject H0
A researcher is evaluating a treatment that is expected to increase scores. If a one-tailed test with a= .05 is used, then the critical region consists of z=scores less than -1.65
False
If a hypothesis test rejects the null hypothesis using an alpha level of a= .05, then the researcher report would include the statement, "p>.05."
False
With a=.05, how are the boundaries for the critical region determined?
Boundaries are drawn so there is 2.5% in each tail o the distribution
A researcher evaluates a treatment effect using a tailed hypothesis test with a= .05, and the decision is to reject the null hypothesis. if the researcher switched to a one-tailed test using the same sample, what decision would be made?
Definitely reject the null hypothesis with a= .05
For a hypothesis test evaluating the effect of a treatment on a population mean, what basic assumption is made concerning the treatment effect?
If there is a treatment effect, it will add (or subtract) a constant to each score
A researcher evaluates a treatment effect using a one-tailed hypothesis test with a= .05, and the decision is to reject the null hypothesis. if the researcher switched to a two-tailed test using the same sample, what decision would be made?
Might reject the null hypothesis with a= .05 but might not
Which of the following accurately describes the critical region?
Outcomes with a very low probability if the null hypothesis is true
A two-tailed hypothesis test is being used to evaluate a treatment effect with a=.05. If the sample data produces a z-score of z= -2.24, what is the correct decision?
Reject the null hypothesis
If a hypothesis test produces a z-score in the critical region, what decision should be made?
Reject the null hypothesis
A researcher conducts a hypothesis test to evaluate the effects of a treatment that is expected to increases scores. The hypothesis test produces a z-sore of z= 2.27. If the researcher is using a one-tailed test, what is the correct statistical decision?
Reject the null hypothesis with a= .05 but not with a= .01
Which of the following is directly addressed by the null hypothesis?
The population after treatment
A researcher conducts a hypothesis test to evaluate the effect of a treatment. the hypothesis test produces a z-score of z= 2.37. Assuming that the researcher is using a two-tailed test, what decision should be made?
The researcher should reject the null hypothesis with a= .05 but not with a= .01
A researcher expects a treatment to increase the scores for individuals in a population. The treatment is evaluated using a one-tailed hypothesis test, and the test produces z= +/-2.40. Based on this result, what is the correct statistical decision?
The researcher should reject the null hypothesis with either a= .05 or a= .01
If the research predict is that the treatment will decrease score, then the critical region for a directional test will be in the left-hand tail
True
In a research report, the term significant result means that the null hypothesis was rejected
True
The critical region for a hypothesis test consists of sample outcomes that are very unlikely to occur if the null hypothesis is true
True
The null hypothesis predicts a specific value for the population mean
True
A researcher expects a treatment to increase the score for individuals in a population. The researcher uses a one-tailed test with a= .01, then which o the following correctly identifies the critical region?
z> 2.33
A researcher is conducting an experiment to evaluate a treatment that is expected to increase the scores for individuals in a population that is known to have a mean of μ= 80. The results will be examined using a one-tailed hypothesis test. Which of the following is the correct statement of the null hypothesis?
μ≤ 80
If the sample data are in the critical region with a= .05, then the same sample data would still be in the critical region if a were changed to .01
False
The null hypothesis states that the sample mean ( after treatment) is equal to the original population mean ( before treatment)
False
