1)

In Chapter 6, youve learned how to construct confidence intervals for population parameters and proportions, based on data from samples.

Respond to the following to describe a "real world" scenario where a researcher might want to construct a confidence interval to support a conclusion about a population parameter.

1. -Provide an overview of the scenario and the variable involved. Include an explanation of why and how constructing the confidence interval adds value. I.e., why might this information be important to know? (4 points)
2. -Identify any assumptions that must be met. (3 points)
3. -Describeanoverviewoftheprocessofconstructingtheconfidenceintervalalongwiththestepsinvolved.(3points)

2)

Scenario:

Behavioral researchers often use statistical techniques to support conclusions about behavioral differences between particular groups of people and the general population of people. This approach has been useful, for example, in identifying memory decrements that result from head injuries. One such study observed participants with lesions in the frontal lobe of the brain, which is thought to be involved in memory functions, and compared their performance on a simple recall task to established norms on the task to see if memory performance was reduced. The normative (general population) data for the task was normally distributed. The researcher measured the performance of 24 people in the sample being studied and compared their scores to the normative data, using an alpha value of .05.

Answer the following regarding the scenario:

1. -State the null and alternative hypotheses, both in words and in symbols. (3 points)
2. -Under the conditions described in the scenario, what statistical test would be appropriate? Explain the rationale for your answer. (3 points)
3. -Would it be most appropriate to use a two-tailed test, a left-tailed test, or a right-tailed test? Why? (2 points)
4. -Inoneparagraph,describetheconclusionyouwouldreachabouttheparticipantsperformanceiftheP-valueofthehypothesistestwasdeterminedtobe.035.Includetherationaleforyourconclusion.(2points)

3)

Scenario:

One well-known psychological experiment measures reaction time (RT) to a stimulus in microseconds (msec). In one version, intended to simulate the effects of texting while driving, participants in an experimental group (EG) are directed to attend to a visual display of words and quickly press a button when a loud noise is heard. A control group (CG) is directed to ignore the visual display and quickly press the button when the noise is heard. Assume the researcher is using an alpha value of .05 in analyzing the results of the experiment, and that she is interested in whether the RT of the experimental group is greater than the RT of the control group. Also assume that RT scores generally tend to be normally distributed, and that the researcher has a sample of at least 30 participants in each group to compare, but that the population parameters are not known.

Answer the following regarding the scenario:

1. -State the null and alternative hypotheses, both in words and in symbols. (3 points)
2. -Under the conditions described in the scenario, what statistical test would be appropriate? Explain the rationale for your answer. (3 points)
3. -Would it be most appropriate to use a two-tailed test, a left-tailed test, or a right-tailed test? Why? (2 points)
4. -In one paragraph, describe the conclusion you would reach about the participants performance if the P-value of the hypothesis test was determined to be .065. Include the rationale for your conclusion. (2 points)