Essentials Of Statistics For The Behavioral Sciences 7th Edition Frederick J. Gravetter, Larry B. Wallnau - Solutions

Unlock the full potential of your learning with our comprehensive solutions for "Essentials of Statistics for the Behavioral Sciences" by Frederick J. Gravetter and Larry B. Wallnau. Access the answers key and solutions manual online to tackle any questions with confidence. Our step-by-step answers guide you through solved problems, ensuring a deep understanding of chapter solutions and textbook content. Utilize our test bank and instructor manual for thorough preparation. All solutions are available for free download in PDF format, providing you with essential tools to excel in your studies.

4. Friedman and Rosenman (1974) have suggested that personality type is related to heart disease. Specifically, type A people, who are competitive, driven, pressured, and impatient, are more prone to heart disease. On the other hand, type B individuals, who are less competitive and more relaxed,
3. A researcher is investigating the physical characterstics that influence whether a person’s face is judged as beautiful. The reseacher selects a photograph of a woman and then creates two modifications of the photo by (1) moving the eyes slightly farther apart and (2) moving the eyes slightly
2. It is well known that similarity in attitudes, beliefs, and interests plays an important role in interpersonal attraction (see Byrne, 1971, for example). Thus, correlations for attitudes between married couples should be strong. Suppose a researcher developed a questionnaire that measures how
1. The following scores are related by the equation Y = X2. Note that this is not a linear relationship, but every time X increases, Y also increases.X Y 2 4 4 16 6 36 8 64 10 100
24. Although the phenomenon is not well understood, it appears that people born during the winter months are slightly more likely to develop schizophrenia than people born at other times (Bradbury & Miller, 1985).The following hypothetical data represent a sample of 50 individuals diagnosed with
23. Cialdini, Reno, and Kallgren (1990) examined how people conform to norms concerning littering. The researchers wanted to determine whether a person’s tendency to litter depended on the amount of litter already in the area. People were handed a handbill as they entered an amusement park. The
22. Research indicates that people who volunteer to participate in research studies tend to have higher intelligence than nonvolunteers. To test this phenomenon, a researcher obtains a sample of 200 high school students. The students are given a description of a psychological research study and
21. Recent reports suggest that children who grow up with pets in the home tend to develop resistence to allergies. To test this phenomenon, a researcher interviews a sample of n 120 college students. Each student is asked about pets during childhood and about his or her current allergies
20. In a study investigating freshman weight gain, the researchers also looked at gender differences in weight(Kasparek, Corwin, Valois, Sargent, & Morris, 2008).Using self-reported heights and weights, they computed the Body Mass Index (BMI) for each student.Based on the BMI scores, the students
19. In a study similar to one conducted by Fallon and Rozin (1985), a psychologist prepared a set of silhouettes showing different female body shapes ranging from somewhat thin to somewhat heavy and asked a group of women to indicate which body figure they thought men would consider the most
18. Gender differences in dream content are well documented (see Winget & Kramer, 1979). Suppose a researcher studies aggression content in the dreams of men and women. Each participant reports his or her most recent dream. Then each dream is judged by a panel of experts to have low, medium, or
17. Research results suggest that IQ scores for boys are more variable than IQ scores for girls (Arden &Plomin, 2006). A typical study looking at 10-year-old children classifies participants by gender and by low, average, or high IQ. Following are hypothetical data representing the research
16. Earlier in this chapter, we discussed a study investigating the relationship between eyewitness memory and the questions they are asked (Loftus & Palmer, 1974).In the study, participants watched a film of an automobile accident and then were questioned about the accident. One group was asked
15. The data form problem 14 show no significant difference between the opinions for city residents and those who live in the suburbs. To construct the following data, we simply doubled the sample size form problem 14 so that all of the individual frequencies are twice as big. Notice that the
14. A local county is considering a budget proposal that would allocate extra funding toward the renovation of city parks. A survey is conducted to measure public opinion concerning the proposal. A total of 150 individuals respond to the survey: 50 who live within the city limits and 100 from the
13. Mulvihill, Obuseh, and Caldwell (2008) conducted a survey evaluating healthcare providers’ perception of a new state children’s insurance program. One question asked the providers whether they viewed the reimbursement form the new insurance as higher, lower, or the same as private
12. In Problem 11, a researcher asked college students to evaluate three new cell phone designs. However, the researcher suspects that college students may have criteria that are different from those used by older adults. To test this hypothesis, the researcher repeats the study using a sample of n
11. A communications company has developed three new designs for a cell phone. To evaluate consumer response, a sample of 120 college students is selected and each student is given all three phones to use for 1 week. At the end of the week, the students must identify which of the three designs they
10. The color red is often associated with anger and male dominance. Based on this observation, Hill and Barton(2005) monitored the outcome of four combat sports(boxing, tae kwan do, Greco-Roman wrestling, and freestyle wrestling) during the 2004 Olympic games and found that participants wearing
9. Automobile insurance is much more expensive for teenage drivers than for older drivers. To justify this cost difference, insurance companies claim that the younger drivers are much more likely to be involved in costly accidents. To test this claim, a researcher obtains information about
8. A professor in the psychology department would like to determine whether there has been a significant change in grading practices over the years. It is known that the overall grade distribution for the department in 1985 had 14% As, 26% Bs, 31% Cs, 19% Ds, and 10% Fs.A sample of n 200
7. Suppose that the researcher from the previous problem repeated the study of married couples’ initials using twice as many participants and obtaining observed frequencies that exactly double the original values.The resulting data are as follows:Same Different Initial Initials 38 362 400a. Use a
6. Research has demonstrated that people tend to be attracted to others who are similar to themselves. One studey demonstrated that individuals are disproportionately more likely to marry those with surnames that begin with the same last letter as their own (Jones, Pelham, Carvallo, & Mirenberg,
5. To investigate the phenomenon of “home-team advantage,” a researcher recorded the outcomes from 64 college football games on one Saturday in October.Of the 64 games, 42 were won by home teams. Does this result provide enough evidence to conclude that home teams win significantly more than
4. Data from the Motor Vehicle Department indicate that 80% of all licensed drivers are older than age 25.a. In a sample of n 60 people who recently received speeding tickets, 38 were older than 25 years and the other 22 were age 25 or younger. Is the age distribution for this sample
3. A developmental psychologist would like to determine whether infants display any color preferences. A stimulus consisting of four color patches (red, green, blue, and yellow) is projected onto the ceiling above a crib. Infants are placed in the crib, one at a time, and the psychologist records
2. The student population at the state college consists of 55% females and 45% males.a. The college theater department recently staged a production of a modern musical. A researcher recorded the gender of each student entering the theater and found a total of 385 females and 215 males. Is the
1. Parametric tests (such as t or ANOVA) differ from nonparametric tests (such as chi-square) primarily in terms of the assumptions they require and the data they use. Explain these differences.
26. A set of n 15 pairs of X and Y values has a correlation of r +.80 with SSY 75, and the regression equation for predicting Y is computed.a. Find the standard error of estimate for the regression equation.b. How big would the standard error be if the sample size were n 30?
25. Problem 9 described a study examining the effectiveness of a 7-Minute Screen test for Alzheimer’s disease. The study evaluated the relationship between scores from the 7-Minute Screen and scores for the same patients from a set of cognitive exams that are typically used to test for
24.a. Briefly explain what is measured by the standard error of estimate.b. How is the magnitude of the standard error of estimate related to the correlation?
23. For the following scores, X Y 3 0 8 10 7 8 5 3 7 7 6 8a. Find the regression equation for predicting Y from X.b. Calculate the predicted Y value for each X.
22. For the following data:a. Find the regression equation for predicting Y from X.b. Use the regression equation to find a predicted Y for each X.c. Find the difference between the actual Y value and the predicted Y value for each individual, square the differences, and add the squared values to
21. A set of n 25 pairs of scores (X and Y values) produce a regression equation of ˆY 2X 7. Find the predicted Y value for each of the following X scores:0, 1, 3, 2.
20. A set of n 20 pairs of scores (X and Y values) has SSX 25, SSY 16, and SP 12.5. If the mean for the X values is M 6 and the mean for the Y values is M 4.a. Calculate the Pearson correlation for the scores.b. Find the regression equation for predicting Y from the X values.
19. The regression equation is intended to be the “bestfitting” straight line for a set of data. What is the criterion for “best fitting”?
17. A researcher measures three variables, X, Y, and Z for each individual in a sample of n 25. The Pearson correlations for this sample are rXY 0.8, rXZ 0.6, and rYZ 0.7.a. Find the partial correlation between X and Y, holding Z constant.b. Find the partial correlation between X and Z, holding Y
16. A researcher would like to evaluate the relationship between a person’s age and his or her preference between two leading brands of cola. In a sample of 12 people, the researcher found that 5 out of 8 people 30 years or older preferred brand A and only 1 out of 4 people younger than 30 years
15. Problem 23 in Chapter 10 presented hypothetical data showing that elderly people who own dogs are significantly less likely to pay visits to their doctors than those who do not own pets. The independent-measures t test produced t 2.11 with df 11 and a value of r 0.288 (28.8%).a. Convert the
14. It appears that there is a significant relationship between cognitive ability and social rank, at least for birds. Boogert, Reader, and Laland (2006) measured social rank and individual learning ability for a group of starlings. The following data represent results similar to those obtained in
13. A common concern for students (and teachers) is the assignment of grades for essays or term papers.Because there are no absolute right or wrong answers, these grades must be based on a judgment of quality.To demonstrate that these judgments actually are reliable, an English instructor asked a
12. As a student, you probably have noticed a curious phenomenon. In every class, there are some students who zip through exams and turn in their papers while everyone else is still on page 1. Other students cling to their exams and continue working until the very last minute. Have you ever
11. As we have noted in previous chapters, even a very small effect can be significant if the sample is large enough. For each of the following, determine how large a sample is necessary for the correlation to be significant. Assume a two-tailed test with .05.(Note: Because the table does not list
10. Assuming a two-tailed test with .05, how large a correlation is needed to be statistically significant for each of the following samples?a. A sample of n 10b. A sample of n 20c. A sample of n 30
9. Identifying individuals with a high risk of Alzheimer’s disease usually involves a long series of cognitive tests. However, researchers have developed a 7-Minute Screen, which is a quick and easy way to accomplish the same goal. The question is whether the 7-Minute Screen is as effective as
8. Correlation studies are often used to help determine whether certain characteristics are controlled more by genetic influences or by environmental influences.These studies often examine adopted children and compare their behaviors with the behaviors of their birth parents and their adoptive
7. For the following set of scores, X Y 3 8 8 1 5 6 6 3 6 6 8 6a. Compute the Pearson correlation.b. Add 2 points to each X value and compute the correlation for the modified scores. How does adding a constant to every score affect the value of the correlation?c. Multiply each of the original X
6. For the following scores, X Y 3 12 6 7 3 9 5 7 3 10
5. For the following scores,a. Sketch a scatter plot showing the six data points.b. Just looking at the scatter plot, estimate the value of the Pearson correlation.c. Compute the Pearson correlation.
4. Calculate SP (the sum of products of deviations) for the following scores. Note: Both means are decimal values, so the computational formula works well:X Y 1 4 4 3 5 9 0 2 X Y 2 4 6 3 1 8 3 5
3. Calculate SP (the sum of products of deviations) for the following scores. Note: Both means are whole numbers, so the definitional formula works well:
2. What information is provided by the numerical value of the Pearson correlation?
1. What information is provided by the sign ( or ) of the Pearson correlation?
4. A recent study of driving behavior suggests that self-reported measures of high driving skills and low ratings of safety skills create a dangerous combination(Sümer, Özkan, & Lajunen, 2006). Note: Those who rate themselves as highly skilled drivers are probably overly confident. Drivers were
3. Briefly describe what is meant by an interaction between factors in a two-factor research study.
2. Loss of hearing can be a significant problem for older adults. Although hearing aids can correct the physical problem, people who have lived with hearing impairment often develop poor communication strategies and social skills. To address this problem, a home education program has been developed
1. Recent research indicates that the effectiveness of antidepressant medication is directly related to the severity of the depression (Khan, Brodhead, Kolts, &Brown, 2005). Based on pre-treatment depression scores, patients were divided into four groups based on their level of depression. After
25. Mathematics word problems can be particularly difficult, especially for primary-grade children. A recent study investigated a combination of techniques for teaching students to master these problems (Fuchs, Fuchs, Craddock, Hollenbeck, Hamlett, &Schatschneider, 2008). The study investigated the
24. The following data are from a two-factor study examining the effects of three treatment conditions on males and females.a. Use an ANOVA with.05 for all tests to evaluate the significance of the main effects and the interaction.b. Calculate the 2 values to measure the effect size for the two
23. The following table summarizes the results from a two-factor study with 3 levels of factor A and 3 levels of factor B using a separate sample of n 9 participants in each treatment condition. Fill in the missing values. (Hint: Start with the df values.)Source SS df MS Between treatments 144
22. The following table summarizes the results from a two-factor study with 2 levels of factor A and 3 levels of factor B using a separate sample of n 8 participants in each treatment condition. Fill in the missing values. (Hint: Start with the df values.)Source SS df MS Between treatments 60
21. Most sports injuries are immediate and obvious, like a broken leg. However, some can be more subtle, like the neurological damage that may occur when soccer players repeatedly head a soccer ball. To examine long-term effects of repeated heading, Downs and Abwender (2002) examined two different
20. A researcher conducts an independent-measures, two-factor study with two levels of factor A and four levels of factor B, using a separate sample of n 10 participants in each treatment condition.a. What are the df values for the F-ratio evaluating the main effect of factor A?b. What are the df
19. The following matrix presents the results from an independent-measures, two-factor study with a sample of n 10 participants in each treatment condition.Note that one treatment mean is missing.Factor B B1 B2 A1 M 20 M 40 Factor A A2 M 50a. What value for the missing mean would result in no main
18. For the data in the following matrix:No Treatment Treatment Male M 5 M 3 Overall M 4 Female M 9 M 13 Overall M 11 overall M 7 overall M 8a. Describe the mean difference that is the main effect for the treatment.b. Describe the mean difference that is the main effect for gender.c. Is there an
17. Briefly explain what happens during the second stage of the two-factor ANOVA.
16. The structure of a two-factor study can be presented as a matrix with the levels of one factor determining the rows and the levels of the second factor determining the columns. With this structure in mind, describe the mean differences that are evaluated by each of the three hypothesis tests
15. Define each of the following terms:a. Factorb. Levelc. Two-factor study
14. A repeated-measures experiment comparing only two treatments can be evaluated with either a t statistic or an ANOVA. As we found with the independentmeasures design, the t test and the ANOVA produce equivalent conclusions, and the two test statistics are related by the equation F t 2.The
13. A recent study indicates that simply giving college students a pedometer can result in increased walking(Jackson & Howton, 2008). Students were given pedometers for a 12-week period, and asked to record the average number of steps per day during weeks 1, 6, and 12. The following data are
12. The following summary table presents the results from a repeated-measures ANOVA comparing four treatment conditions, each with a sample of n 10 subjects. Fill in the missing values in the table.(Hint: Start with the df values.)Source SS df MS Between treatments 20 F 5.00 Within treatments 158
11. A researcher is evaluating the effectiveness of a speed-reading course. A standardized reading test, measuring both speed and comprehension, was given to a sample of n 15 students before the course started and again at the end of the course. The following table presents the results from the
10. The following data are from an experiment comparing three different treatment conditions:ABC 012 N 15 255 X2 354 126 549 288 T 10 T 20 T 30 SS 14 SS 30 SS 30a. If the experiment uses an independent-measures design, can the researcher conclude that the treatments are significantly different?
9. The following data were obtained from a repeatedmeasures study comparing three treatment conditions.a. Use a repeated-measures ANOVA with.05 to determine whether there are significant mean differences among the three treatments.b. Compute 2, the percentage of variance accounted for by the mean
8. The following data were obtained from a repeatedmeasures study comparing two treatment conditions.Use a repeated-measures ANOVA with.05 to determine whether there are significant mean differences between the two treatments.Treatments Person Person I II Totals A35 P 8 B59 P 14 N 16 C15 P 6 G 80
7. The following data were obtained from a repeatedmeasures study comparing three treatment conditions.Use a repeated-measures ANOVA with.05 to determine whether there are significant mean differences among the three treatments.Treatments Person Person I II III Totals A 0 42 P 6 B 1 56 P 12 N 18 C
6. A published report of a repeated-measures research study includes the following description of the statistical analysis. “The results show significant differences among the treatment conditions, F(2, 20) 6.10, p .01.”a. How many treatment conditions were compared in the study?b. How many
5. A researcher uses a repeated-measures ANOVA to evaluate the results from a research study and reports an F-ratio with df 3, 36.a. How many treatment conditions were compared in the study?b. How many individuals participated in the study?
4. A researcher conducts a repeated-measures experiment using a sample of n 10 subjects to evaluate the differences among three treatment conditions. If the results are examined with an ANOVA, what are the df values for the F-ratio?
3. A researcher conducts an experiment comparing three treatment conditions. The data consist of n 20 scores for each treatment condition.a. If the researcher used an independent-measures design, then how many individuals were needed for the study and what are the df values for the F-ratio?b. If
2. The repeated-measures ANOVA can be viewed as a two-stage process. What is the purpose for the second stage?
1. How does the denominator of the F-ratio (the error term) differ for a repeated-measures ANOVA compared to an independent-measures ANOVA?
22. First-born children tend to develop language skills faster than their younger siblings. One possible explanation for this phenomenon is that first-borns have undivided attention from their parents. If this explanation is correct, then it is also reasonable that twins should show slower language
21. One possible explanation for why some birds migrate and others maintain year round residency in a single location is intelligence. Specifically, birds with small brains, relative to their body size, are simply not smart enough to find food during the winter and must migrate to warmer climates
20. The following data represent the results from an independent-measures study comparing two treatment conditions.a. Use an independent-measures t test with .05 to determine whether there is a significant mean difference between the two treatments.b. Use an ANOVA with .05 to determine whether
19. The following values summarize the results from an independent-measures study comparing two treatment conditions.a. Use an independent-measures t test with .05 to determine whether there is a significant mean difference between the two treatments.b. Use an ANOVA with .05 to determine
18. The following data were obtained from an independentmeasures research study comparing three treatment conditions. Use an ANOVA with .05 to determine whether there are any significant mean differences among the treatments.Treatment I II III 25 7 N 14 52 3 G 42 01 6 X2 182 12 4 22 T 12 T 10 T
17. A developmental psychologist is examining the development of language skills from age 2 to age 5.Four different groups of children are obtained, one for each age, with n 15 children in each group. Each child is given a language skills assessment test. The resulting data were analyzed with an
16. A pharmaceutical company has developed a drug that is expected to reduce hunger. To test the drug, three samples of rats are selected with n 10 in each sample. The first sample receives the drug every day.The second sample is given the drug once a week, and the third sample receives no drug at
15. The following summary table presents the results from an ANOVA comparing three treatment conditions with n 12 participants in each condition. Complete all missing values. (Hint: Start with the df column.)Source SS df MS Between treatments 9 F Within treatments Total 117
14. There is some evidence that high school students justify cheating in class on the basis of poor teacher skills or low levels of teacher caring (Murdock, Miller, and Kohlhardt, 2004). Students appear to rationalize their illicit behavior based on perceptions of how their teachers view cheating.
13. A research report from an independent-measures study states that there are significant differences between treatments, F(2, 54) 3.58, p < .05.a. How many treatment conditions were compared in the study?b. What was the total number of participants in the study?
12. A researcher reports an F-ratio with df 3, 36 from an independent-measures research study.a. How many treatment conditions were compared in the study?b. What was the total number of participants in the study?
11. Binge drinking on college campuses has been a hot topic in the popular media and in scholarly research. Flett, Goldstein, Wall, Hewitt, Wekerle, and Azzi (2008) report the results of a study relating perfectionism to binge drinking. In the study, students were classified into three groups based
10. For the preceding problem you should find that there are significant differences among the three treatments. One reason for the significance is that the sample variances are relatively small. To create the following data, we started with the values from problem 9 and increased the variability
9. The following data summarize the results from an independent-measures study comparing three treatment conditions.I II III n 5 n 5 n 5 M 2 M 5 M 8 N 15 T 10 T 25 T 40 G 75 SS 16 SS 20 SS 24 ΣX2 525a. Calculate the sample variance for each of the three samples.b. Use an ANOVA with .05 to
8. For the preceding problem you should find that there are significant differences among the three treatments. The primary reason for the significance is that the mean for treatment I is substantially smaller than the means for the other two treatments. To create the following data, we started
7. The following data summarize the results from an independent-measures study comparing three treatment conditions.I II III n 6 n 6 n 6 M 1 M 5 M 6 N 18 T 6 T 30 T 36 G 72 SS 30 SS 35 SS 40 ΣX2 477a. Use an ANOVA with α .05 to determine whether there are any significant differences among the
6. The following data represent the results from an independent-measures study comparing three treatments.a. Compute SS for the set of 3 treatment means.(Use the three means as a set of n 3 scores and compute SS.)b. Using the result from parta, compute n(SSmeans).Note that this value is equal to
5. Posttests are done after an ANOVA.a. What is the purpose of posttests?b. Explain why you would not do posttests if the analysis is comparing only two treatments.c. Explain why you would not do posttests if the decision from the ANOVA was to fail to reject the null hypothesis.

Showing 2600 - 2700 of 5165

First
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
Last

Essentials Of Statistics For The Behavioral Sciences 7th Edition Frederick J. Gravetter, Larry B. Wallnau - Solutions

Step by Step Answers