PSY 418
The Frayed Nerves Anxiety Scale (FNAS) is used to measure the anxiety
level of people on a scale from 0 to 1000. Four 418 students were
randomly chosen and given the FNAS before their second exam. Their
scores were 700, 653, 740, and 707. She standard deviation sigma of
the test is 40.
1. What is x bar?
2. What is the standard deviation of the mean?
3. What is the 95% confidence interval for x bar?
4. What is the 99% confidence interval for x bar?
5. How many 418 students do you need to survey to get the plus or minus
for the 95% confidence interval down to 20?
6. How about for the 99% confidence interval?
7. A TA for the 418 class states that the mean stress level of the
class is 750. The professor is not so sure. Take the TA's belief as
the null hypothesis. Remember, only four subjects were run.
a. State the null and alternative hypotheses
b. Calculate the p-value for the null hypothesis.
c. Is it significant with alpha equal to .05?
d. Is it significant with alpha equal to .01?
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8. For your second paper, you will conduct an experiment on your fellow classmates. This will be a group project. Form a group with students from your lab section. Groups should consist of four or five people. Your experiment will manipulate an independent variable with two levels. Your dependent measure will be a continuous measure (e.g., rating scale, response time, etc.).
a. list your group members.
b. Working alone or with members of your group, state an idea you have for an experiment. Specify the indenpendent and dependent variable, as well as your prediction. You are not required to do a literature search yet, but feel free to use PyschInfo, http://www.lib.utexas.edu/indexes/titles.html?let=P