Please highlight or circle the correct answers

1. Descriptive statistics are used to organize data sets to describe a set of characteristics. What are inferential statistics used for?
   1. To turn statistics into a disco inferno.
   2. To make statements about a population based on a sample.
   3. To present information to the public.
   4. To conduct research, as descriptive statistics are not useful for research.
2. What is the difference between an independent and a dependent variable?
   1. A dependent variable changes based on the independent variable(s).
   2. no need to measure the independent variable.
   3. no need to measure the dependent variable.
   4. An independent variable changes based on the dependent variable(s)
3. The four levels of measurement in order are:
   1. Ratio, Nominal, Interval, Ordinal
   2. Categorical, Binary, Interval, Ratio
   3. Binary, Interval, Ratio, Categorical
   4. Nominal, Ordinal, Interval, and Ratio
4. Two parallel forms of the same ADHD test were given to high school students, but were only had a correlation of .31 with each other. Based on this data, what can we say about this test?
   1. The test has poor parallel forms reliability.
   2. This test has poor test-retest reliability.
   3. This test has poor criterion validity.
   4. This test has poor construct validity.
5. The same test had only a .23 correlation with another, more established measure of ADHD. Based on this data, what else can we say about this test?
   1. The test has poor parallel forms reliability.
   2. This test has poor test-retest reliability.
   3. This test has poor criterion validity.
   4. This test has poor construct validity.
6. What is an alpha level () in an experiment?
   1. Chance of type II error.
   2. Chance of type I error.
   3. A metric to compare your p-value to.
   4. Both b and c.
7. How can you improve your study power, represented by 1-?
   1. Reducing the sample size.
   2. Lowering your alpha level.
   3. Increasing the sample size.
   4. Both a and b.
8. Your alpha level for a two-tailed independent t-test was .05. Your p-value is .04. What statement can you make about the hypotheses with this information?
   1. Retain the null hypothesis.
   2. Retain the research/alternative hypothesis.
   3. Reject the research/alternative hypothesis.
   4. Reject the null hypothesis.

1. In the same study, the effect size was .19. What statement can you make about the data based on this new information?
   1. There was a large difference between the two means.
   2. There was a small difference between the two means.
   3. The two means are equal.
   4. The results of this study are insignificant.
2. You conducted a two-tailed z-test at the .05 significance level, and your result was 1.16. What statement can you make about the difference between the sample and the population based on this data?
   1. The sample mean was significantly different than the population mean.
   2. The sample data was always 1.16 standard deviations above the population mean.
   3. The sample was not significantly different from the population mean.
   4. The sample must be skewed compared to the population.

Short answer questions (5 questions, 50 points total)

You are a researcher trying to understand how therapist height may affect client satisfaction in therapy. You decide to examine male therapists to avoid a bimodal distribution.Please use this dataset to answer the following questions.

1. Measures of central tendency and variability:
   1. What is the mean of the HEIGHT dataset? (1 point)

1. What is the median of the HEIGHT dataset? (1 point)

1. What is the mode of the HEIGHT dataset? (1 point)

1. What is the range of the HEIGHT dataset? (1 point)

1. What is the standard deviation of the HEIGHT dataset? (1 point)

1. What is the number of observations in this dataset? (n) (1 point)
2. Graphs and distributions (Continue with the HEIGHT dataset):
   1. Create a histogram that accurately represents the data. (5 points)

1. Is there skew in this distribution? Why or why not? (2 points)

1. Assuming the data is normally distributed, what percentage of the data falls below the mean? (2 points)

1. Z-scores (continue with the HEIGHT dataset):
   1. Dr. Max is 70 inches tall. What is his z-score if he was in this sample of therapists? (1 point)

1. What would the z-score be for a therapist who is 78 inches tall? (1 point)

1. You learn the following population parameters about adult US male height. Based on this information, conduct a two-tailed z-test at the .05 significance level and report your test statistic. Be sure to report your code from Sheets/Excel or show your work. (3 points)

= 69.1 inches

= 3 inches

1. What z-score would you compare the z-statistic to if the test was at the .05 significance level? (1 point)

1. Based on these data, what statement can we make about this sample of male therapists compared to the population of men in the US? (3 points)

1. What is the effect size for this z-test? (2 points)
2. You took a sample of "tall" therapists and "average height" therapists and found their average client satisfaction survey scores. Now you want to know if "tall" therapists truly do have more satisfied clients. Look at "Sheet 2" at the bottom ofthis Google Sheet to find the data for this question.

1. What statistical test would you use to find the answer to this question? (2 points)

1. In your own words, what are the null and research/alternative hypotheses here? (2 points)

1. You decide to use a significance level of .05. What is the p-value for this test? Be sure to report your code or show your work. (3 points)

1. Based on your p-value, what statement can you make about the null hypothesis? (3 points)

1. Based on your sample, what can we say about the clients of tall male therapists? (2 points)
2. You decide you want to make your research spicy. So, you give the existing clients of your tall therapists a fake research article that says that tall therapists have been shown to be more effective than short therapists. You give them a satisfaction survey before they read the article and then after 3 months of additional therapy. You want to see if this results in higher client satisfaction scores. Look at "Sheet 3" at the bottom ofthis Google Sheet to find the data for this question.

1. What statistical test would you use to find the answer to this question? (2 points)

1. In your own words, what are the null and research/alternative hypotheses here? (2 points)

1. You decide to use a significance level of .01. What is the p-value for this test? Be sure to report your code or show your work. (3 points)

1. Based on your p-value, what statement can you make about the null hypothesis? (3 points)

1. Based on your experiment, did the fake research article have an effect on these clients? Why or why not? (2 points)