Practice Problems (Chapters 7 and 8)
Chapter7
1. Which would youexpect to be more variable: (a) the distribution of scores in apopulation or (b) the distribution of sample means based on randomsamples of 25 cases from this population. Explain.
- Given a normal distribution of scores that has a mean of 50 anda standard deviation of 10, what is the probability of selecting ascore that is greater than 65? If a random sample of 10 scores wereselected from this population, what is the probability that themean score for this sample would be greater than 65?
- In a short paragraph, explain the logic of inferentialstatistics (The Hinkle et al. text refers to this as the chain ofreasoning in inferential statistics).
- What is the central limit theorem and what role does it play ininferential statistics?
Chapter8
- Describe a study in which a one sample t-test is appropriate.Be sure to state your research question, hypotheses, significancelevel, critical value, etc.
- List the steps in the hypothesis testing sequence.
- In a short paragraph, explain Type I and Type II errors to anaudience that has no previous experience with statistics.
8. What is meant bystatistical significance? Why does your author suggest that it maynot always be adequate for purposes of research?
9. Provide anexample of the following: (a) A research problem appropriate for anon-directional test using the one-sample z-statistic. (b) Aresearch problem appropriate for a directional test using theone-sample t-statistic.
10. Consider the data inproblem 11 in the text (page 199). Enter these data into SPSS andconduct a test of the null hypothesis.
