test 3 AA

Multiple Choice

Identify the choice that best completes the statement or answers the question.

____    1.   For an ANOVA comparing three treatment conditions, what is stated by the alternative hypothesis (H₁)?

____    2.   On average, what value is expected for the F-ratio if the null hypothesis is true?

____    3.   A research study comparing three treatments with n = 5 in each treatment produces T₁ = 5, T₂ = 10, T₃ = 15, with SS₁ =  6, SS₂ = 9, SS₃ = 9, and SX² = 94. For this study, what is SS_between?

____    4.   An analysis of variance produces SS_between = 30, SS_within  = 60, and an F-ratio with df = 2, 15. For this analysis, what is the F-ratio?

____    5.   If an analysis of variance is used for the following data, what would be the effect of changing the value of M₁ to 20?

Sample Data

M₁ = 15      M₂ = 25

SS₁ = 90    SS₂ = 70

____    6.   In general, what factors are most likely to reject the null hypothesis for an ANOVA?

____    7.   A two-factor study with two levels of factor A and three levels of factor B uses a separate group of n = 5 participants in each treatment condition. How many participants are needed for the entire study?

____    8.   The following data represent the means for each treatment condition in a two-factor experiment. Note that one mean is not given. What value for the missing mean would result in no A´B interaction?

B1         B2

____    9.   If a two-factor analysis of variance produces a statistically significant interaction, what can you conclude about the main effects?

____  10.   What is indicated by a positive value for a correlation?

____  11.   The scatter plot for a set of X and Y values shows the data points clustered in a nearly perfect circle. For these data, what is the most likely value for the Pearson correlation?

____  12.   What is indicated by a Pearson correlation of r = +1.00 between X and Y?

____  13.   What is the value of SP for the following set of data?

______________

____  14.   Suppose the correlation between height and weight for adults is +0.40. What proportion (or percent) of the variability in weight can be explained by the relationship with height?

____  15.   As the sample size gets larger, what happens to the size of the correlation that is needed for significance?

____  16.   Under what circumstances is the phi-coefficient used?

____  17.   A set of X and Y scores has M_X = 4, SS_X = 10, M_Y = 5, SS_Y = 40, and SP = 20. What is the regression equation for predicting Y from X?

____  18.   A linear regression equation has b = 3 and a = – 6. What is the predicted value of Y for X = 4?

____  19.   A set of n = 25 pairs of scores (X and Y values) has a Pearson correlation of r = 0.80. How much of the variance for the Y scores is predicted by the relationship with X?

____  20.   Which of the following best describes the possible values for a chi-square statistic?

____  21.   What conclusion is appropriate if a chi-square test produces a chi-square statistic near zero?

____  22.   A researcher is using a chi-square test to determine whether people have any preferences among three brands of televisions. The null hypothesis for this test would state that ______.

____  23.   A sample of 100 people is classified by gender (male/female) and by whether or not they are registered voters. The sample consists of 80 females and 20 males, and has a total of 60 registered voters. If these data are used for a chi-square test for independence, what is the total number of females for the expected frequencies?

____  24.   A researcher selects a sample of 100 people to investigate the relationship between gender (male/female) and registering to vote. The sample consists of 40 females, of whom 30 are registered voters, and 60 males, of whom 40 are registered voters. If these data were used for a chi-square test for independence, what is the observed frequency for registered males?

Short Answer

25. A psychologist would like to examine the effects of different testing methods on the final performance of college students. One group gets regular quizzes, one group gets three large exams, and the third group only gets a final exam. At the end of the course, the psychologist interviews each student to get a measure of the student’s overall knowledge of the material.

Please show your manual calculations

5. Do these data indicate any significant differences among the three methods? Test with á = .05.
6. Compute Tukey’s HSD to determine exactly which methods are significantly different.

26. Compute the Pearson correlation for the following data. Please show your manual calculations

27. A researcher is examining preferences among four new flavors of ice cream. A sample of n = 80 people is obtained. Each person tastes all four flavors and then picks his/her favorite. The distribution of preferences is as follows.

Ice Cream Flavor

A          B           C         D

Do these data indicate any significant preferences among the four flavors? Test at the .05 level of significance.

28. A researcher would like to know whether there is a consistent, predictable relationship between verbal skills and math skills for high school students. A sample of 200 students is obtained, and each student is given a standardized English test and a standardized math test. Based on the test results, students are classified as high or low for verbal skills and for math skills. The results are summarized in the following frequency distribution:

Verbal Skills

High              Low

1. Based on these results, can the researcher conclude that there is a significant relationship between verbal skills and math skills? Test at the .05 level of significance.
2. Compute the phi-coefficient to measure the strength of the relationship.

29           A researcher is interested in the relationship between GPA and Sorority/Fraternity membetrship.  She conducted a study with 5 soroity women and 5 non sorority women.  She also included 5 male in a fraternity and five males who were not members of a fraternity.   She gathered the GPS’s of each and analyzed using spss, which produced the following tables:

Cell Means

Gender

Female                   Male

Member                 3.3                      3.1

Non-member             3.6                     3.4

Tests of Between Subjects Effects

Source                Type III Sum Squares       df     Mean Square       F         Sig

Gender                   500                       1            500         2.0        .35

Member                 1000                        1          1000         5.6        .045

Gender*member          250                        1           250          3.5        .89

Error                      3300                                  200

FIRST      draw a LINE GRAPH  showing CELL MEANS

SECOND    Interpret the results table of Between Subjects Effects.  That is,  Were there any main effects

or interaction effects, AND why do you say that.