stats 280

1. In life, most well-adjusted people want to get along and to get ahead, and also to find meaning. According to Hogan and Blickle (2013), social skills are important to accomplishing the first two goals, and may also help people find meaning as well. In a study of career achievement using a sample of 6 working adults, Dr. Keepinitreal examined the relationship between social skill ratings and the number of promotions each person received during their careers. Each participant was rated by three close associates (friends/family/coworkers) on a measure of social skills, where higher overall scores represent better social skills. Each participant then indicated how many promotions they had received in their jobs during the past 10 years. The data are shown below.

2.

a. Fill in the table above. 2.5 pts

b. What are the two variables in the study? 1 pt

c. What are the hypotheses in this study? 1 pts

d. What are the degrees of freedom for this statistical test? 1 pt

e. What is the critical value for this test? 1 pt

f. Calculate the test statistic (r) for this study. 2 pts

g. What is the direction of this correlation? Interpret what the direction of the correlation means in the context of this study? 1 pt

h. How would you interpret the strength of this correlation? Why? 1 pt

i. Make a statistical decision about the null. Will you reject or fail to reject the null based on your sample data? Why? 1 pt

j. What do your results mean in words a layman would understand? 1 pt

k. Sketch a scatterplot of the data by hand. 1 pt.

3. Look at the correlation matrix below, and answer the following questions:

a. What is the correlation between Income and School Readiness? ½ point

b. What is the proportion of variance in School Readiness that is accounted for by Income? Is this a small, medium, or large effect? 1 point

c. What percent of the variance in School Readiness is not accounted for by Income? ½ point

4. Open the ‘Homework 12 Dataset_F18.sav’ file for this problem.

Dr. SAT, a future marketing expert, is wondering if there is a correlation between the amount of bubble tea drinks someone has a week and the person’s happiness. Dr. SAT thinks that because bubble tea is so delicious, the more that people drink it, the happier they will be. He samples 10 college students, who each report the amount of bubble tea drinks they have had the past week and then complete a measure of happiness, where higher scores indicate greater happiness. To conduct a correlation, go to Analyze>Correlate>Bivariate. Move variables to the Variables box. Click OK to run the test.

a. Attach a copy of your output to the homework. 1 pt

b. What are the variables in this study? 1 pt

c. What is the obtained r for the correlation? 1 point

d. Using the p value from the SPSS output, make a statistical decision about the correlation, assuming α = .05. 1.5 pt