HTH 320 Exam 2

The correlation coefficient ranges between ____ and ____.

-1 and +1

This study consists of monthly totals of airline passengers from January 1949 to December 1960. Sample size: n = 144 Variables in the data set: Number: the monthly passenger totals in thousands. Calculate the skewness:

2.89

Which of the following statements is the appropriate way to read the degrees of freedom for an ANOVA with 10 participants in each of four groups?

3 and 36

A researcher measures the relationship between narcissism and willingness to help. If SSxy= 240, SSx= 320, and SSy = 410, then what is the value of the correlation coefficient?

,66

Which of the following indicates the strongest correlation?

-.9

A researcher compares differences in positivity between participants in a low-, middle-, or upper-middle-class family. If she observes 15 participants in each group, then what are the degrees of freedom for the one-way between-subjects ANOVA?

(2, 42)

Interpret the Tukey post hoc test results for the different levels of education, which can be found in the Multiple Comparisons table, as shown below

A. From the results, we can see that there is a statistically significant difference between all three different educational levels (p < .05).

An unanticipated variable not accounted for in a research study that could be causing or associated with observed changes in one or more measured variables is called

Confound variable

If a two-sample data do not meet the normality or the homogeneity of variance, what type of tests you can use?

Mann-Whitney Test

10. A researcher randomly assigned 32 children to observe a short clip depicting either their favorite superhero, a parent, a teacher, or no person at all (n = 8 per group). If SSBG= 30 and SSE = 104, then what was the decision at a .05 level of significance for a one-way between-subjects ANOVA?

Retain the null hypothesis

If the variable is not normally distributed, you might want to do transformation to make it normal. Which type of transformation is appropriate for the data?

Since the variable "number" is positively skewed data and Normal Q-Q plot also shows a nonlinear LOG pattern, transfer this variable into the "LG10 (number)".

There are several eyeball tests for the normality, Normal Q-Q Plots and Histogram are two best methods. Check the graphs, which one is correct from the visual inspection of the graphs?

The Normal Q-Q Plots shows that data points are not lie around the straight diagonal line, the data is not normally distributed.

A researcher measures the following correlation between cups of coffee consumed daily and daily work schedule. Which description best explains the relationship between these two factors?

he more a person works, the more coffee he or she tends to drink.

For an analysis of variance, the term "one-way" refers to

the number of factors in the design

A researcher assigned participants (n = 8 per group) to read vignettes describing a person engaging in either a helpful, hurtful, or neutral act. Different participants were assigned to each group and asked to rate how positively they viewed the person described in the vignette. What is the critical value for the one-way between-subjects ANOVA at a .05 level of significance?

3.47

The Kolmogorov-Smirnov test and the Shapiro-Wilk test are commonly used to assess normality of the data. Given this dataset, which test will be appropriate to help you make the right decision about the normality? Tests of Normality Kolmogorov-Smirnova Shapiro-Wilk Statistic df Sig. Statistic df Sig. number .101 144 .001 .952 144 .000

The assumption of normality for 'number' was not satisfied, as assessed by Kolmogorov-Smirnov test (p < .05).

What's your interpretation of the result from the Levene's test: Test of Homogeneity of Variances Engagement with TV advert Levene Statistic df1 df2 Sig. 1.922 1 38 .174

The p value=0.174 > .05, so there is homogeneity of variance.

Based on the skewness you calculated, is this variable normally distributed?

The skewness value out of ±2.58, the data is not normally distributed.

A two-way ANOVA was conducted that examined the effect of gender and education level on interest in politics.

There was a statistically significant interaction between the effects of gender and education level on interest in politics, F (2, 54) = 4.643, p = .014.

A Pearson product-moment correlation was run to determine the relationship between height and distance jumped in a long jump. Please interpret the correlation result.

There was a strong, positive correlation between height and distance jumped, which was statistically significant (r = .706, n = 14, p = .005).