statistic assignment

Notes for your submission:

1) Put your document into Microsoft Word, .txt, or pdf. Do not turn in a file directly from Apple’s Pages.

2) When full sentences or essays are asked for, you can lose points for poor writing.

3) For the math problems, please show your work.

4) The test is out of 100 points. Each question is worth 10 points. There are 2 bonus questions for additional points.

Question 1 Survey construction

Attached is a copy of a past Childcare survey that SUSB sent to all students, faculty, and staff. Pretend that the committee came to you with this survey as a draft and asked you for your feedback. Provide 5 specific suggestions for them to improve their survey. If you don’t think I’ll understand why your suggestion would be useful, include a 1-2 sentence explanation. Label these suggestions A, B, C, D, and E so I can easily see your suggestions. The survey would be given online so don’t comment on the spacing.

Question 2 Levels of Variables

In the childcare study state the level of variable (binary, nominal, ordinal, interval, and ratio) for the listed survey questions. Provide a one sentence justification for each.

A) Question 1 (2 points)

B) Question 2 (2 points)

C) Question 5 (2 points)

D) Question 17 (2 points)

E) The survey does not use a Likert scale. What would be the level of variable for a Likert scale (Note: your justification is very important on this question – 2 points)

Question 3 Qualitative study

The Childcare survey is mostly quantitative. Write a paragraph describing how you might qualitatively gather data to do a “preliminary exploration of possible childcare options.” You do not have to use a survey like this one as part of your method.

Question 4 Factorial Studies

If you have a study that is a 2x3x2 factorial

A) How many independent variables are there? (2 points)

B) How many levels for each independent variable? (2 points)

C) How many conditions are there? (2 points)

D) How many potential main effects are there to examine? (2 points)

E) What is the level of variable (binary, nominal, ordinal, interval, ratio) that is represented by the first 2 in the 2x3x2 factorial?

Bonus question (+2 points)

Construct a 2x2 factorial table that has no significant main effects but has a significant interaction.

Question 5 Between/within studies

A) Define the terms between-participants study and within-participants study. (2 points)

B) State an advantage of between-participant study (2 points)

C) State an advantage of a within-participant study (2 points)

D) Why is random assignment to conditions not appropriate for a within-participant study? (2 points)

E) For the 2x3x2 factorial study in the previous question, do we know which variables are between and which variables are within?

Question 6 Quasi-experiment

A) This question uses the attached Pasto and Baker (2001) study. In 1-2 sentences describe why the Pasto and Baker study is a quasi-experiment. (2 points)

B) Recently President-Elect Trump mentioned that he would in the first year deport 2-3 million illegal immigrants, with the implication that this is a large number for deportation. Only having this information mimics a poor quasi-experimental design. What is another piece of information that is needed to know if 2 to 3 million is a high number? (2 points)

B) Evaluate the internal validity of the Pasto and Baker study (3-5 sentences – 6 points)

Bonus question (+2 points)

Make a specific, practical suggestion that would improve the internal validity of the Pasto and Baker study. (1-3 sentences)

Question 7 Experiment

The Pasto and Baker (2011) study is a quasi-experimental design. In a paragraph describe how you could do a true experiment that is a conceptual replication of this study. Remember as this is a conceptual replication, the study could look very different; it just needs to test the same hypothesis.

Question 8 Frequencies

A) Look in the Pasto and Baker (2001) study at Figure 1. Redraw Figure 1 (by hand is acceptable) such that the values on y-axis (i.e., the frequencies) go from 0 to 75 instead of 60 to 75. (2 points)

B) Now look at the graph you made for part A. Describe how it looks different from the figure in the article (1 sentence). Which of the two figures is biased and why (1 sentence answer)? (2 points)

C) Based on Figure 1 and Figure 2, does it look like the intervention had more of an effect on the drivers or the passengers? Defend your answer in 1-2 sentences (2 points)

D) Based on Table 1 (not Figure 1) in the Pasto and Baker (2001) study, how many people in total were observed? (2 points)

E) Based on Table 1, determine what percentage of cars had a front passenger? (2 points)

Question 9 Central Tendency

A) Which of the three measures of central tendency (mean, median, mode) can you use with nominal data? (2 points)

B) Which measure of central tendency is most affected by outliers? (2 points)

C) Can a measure of central tendency ever be below 0? If yes, provide a small dataset (e.g., n=3) that has the mean less than 0. (2 points)

D) If you were a server at a restaurant and you wanted to find the central tendency of the percentage tip (e.g., 20%) you received, which measure of central tendency would you use? Defend your answer in 1-2 sentences. (4 points)

Question 10 Weighted means

A student has made the following grades in class so far:

Essay 1 (worth 10% of the course grade) 85

Essay 2 (worth 20% of the course grade) 82

Midterm (worth 30% of the course grade) 87

Final (worth 40% of the course grade) Not yet taken

A) The student says that their current class grade (not including the Final) is probably a low A (i.e., around 90-93). Why do you know without calculation that is not correct? (one sentence answer – 2 points)

B) If the highest possible grade on the Final is a 100, what is the highest grade overall the student could make? (4 points)

C) What grade does the student need to make on the Final to get an overall grade of 90? (4 points)