Exam 7: Sampling and Inferential Statistics

Exhibit 7-2: Label the following characteristics of sampling procedures as convenience, purposive, or quota. -Refer to Exhibit 7-2.Taking subjects wherever you find them.

Exhibit 7-2: Label the following characteristics of sampling procedures as convenience, purposive, or quota. -Refer to Exhibit 7-1.All individual cases have a non-zero chance of being selected.

Explain what a p value means?

A researcher wants a 90 percent chance of rejecting the null hypothesis at the one-tailed .05 level with an effect size of .15.The sample size needed is about

Exhibit 7-13: An investigator wished to look at the relationship between the aspirations of high school juniors for a college education and their current grade point averages.He asked 150 high school juniors whether or not they wanted to attend college.The following data were obtained: GPA Below average Average Above average Aspiration Yes 15 25 35 to attend College No 35 25 15 Apply the X² test to the above data and then answer the following questions. -Refer to Exhibit 7-13.The expected frequency for above-average students who want to attend college is

Which of these errors, Type I or Type II, does power influence? Give an example of a study where a one-tailed test would be appropriate.

Exhibit 7-6: A group of researchers hypothesizes that listening to music while studying for an exam influences test scores.They randomly selected 28 subjects and divided them into four groups.All groups studied silently for a test for an hour a day for a week.Group 1 studied without music.Group 2 studied with classical music in the background, Group 3 with country, and Group 4 with jazz.The following are the final test scores: Group 1 Group 2 50 59 45 57 42 57 41 55 40 56 39 53 38 51 Group 3 Group 4 60 49 56 45 56 45 55 42 54 41 51 39 50 37 -Refer to Exhibit 7-6.What is the value for the chosen statistic?

Exhibit 7-10: Choose the appropriate statistic for the following situations. -Refer to Exhibit 7-10.Do customers spend more through a store's catalog or in person at the store?

Exhibit 7-7: A group of curriculum designers has developed a new system for teaching phonics to young children.They randomly selected 24 kindergarten students to receive either the old phonics method or the new phonics method.The designers realized that kindergartens have morning and afternoon classes, so they wanted to build this factor into the research design.The following is the mean, standard deviation, and number for each group. Morning Old New 16.33 13.50 1.03 2.74 6 6 Afternoon 13.17 16.83 3.55 2.14 6 6 The following is an incomplete summary table of the analysis of variance: Time of Day 0.042 Lesson Design 1.042 Interaction Error 128.500 Total 102950 -Refer to Exhibit 7-7.What are the degrees of freedom for the Interaction?

Exhibit 7-10: Choose the appropriate statistic for the following situations. -Refer to Exhibit 7-10.Do college graduation and generation membership influence the amount of money people are willing to be spend on a house?

Exhibit 7-7: A group of curriculum designers has developed a new system for teaching phonics to young children.They randomly selected 24 kindergarten students to receive either the old phonics method or the new phonics method.The designers realized that kindergartens have morning and afternoon classes, so they wanted to build this factor into the research design.The following is the mean, standard deviation, and number for each group. Morning Old New 16.33 13.50 1.03 2.74 6 6 Afternoon 13.17 16.83 3.55 2.14 6 6 The following is an incomplete summary table of the analysis of variance: Time of Day 0.042 Lesson Design 1.042 Interaction Error 128.500 Total 102950 -Refer to Exhibit 7-7.Which of the following is associated with greatest power

Exhibit 7-4: A group of researchers has developed a method that they hypothesize will improve physics test scores.They randomly selected nine students to participate in their study.The nine students were administered an ACT test, trained in the new method, and then administered an alternate form of the ACT test.The following data are their scores: Subject Test 1 Test 2 1 20 19 2 20 20 3 24 21 4 24 24 5 24 22 6 17 15 7 18 15 8 18 16 9 20 18 -Refer to Exhibit 7-4.The researchers can conclude that:

Exhibit 7-8: A pet store owner buys equal amounts of supplies for all types of animals.She wonders if the proportions of her customers are equal or are the same.She collected the following data over a period of a week: Customers 46 48 35 28 28 -Refer to Exhibit 7-8.The store owner

Exhibit 7-6: A group of researchers hypothesizes that listening to music while studying for an exam influences test scores.They randomly selected 28 subjects and divided them into four groups.All groups studied silently for a test for an hour a day for a week.Group 1 studied without music.Group 2 studied with classical music in the background, Group 3 with country, and Group 4 with jazz.The following are the final test scores: Group 1 Group 2 50 59 45 57 42 57 41 55 40 56 39 53 38 51 Group 3 Group 4 60 49 56 45 56 45 55 42 54 41 51 39 50 37 -Refer to Exhibit 7-6.What test is most appropriate for this data and hypothesis?

Exhibit 7-4: A group of researchers has developed a method that they hypothesize will improve physics test scores.They randomly selected nine students to participate in their study.The nine students were administered an ACT test, trained in the new method, and then administered an alternate form of the ACT test.The following data are their scores: Subject Test 1 Test 2 1 20 19 2 20 20 3 24 21 4 24 24 5 24 22 6 17 15 7 18 15 8 18 16 9 20 18 -Refer to Exhibit 7-4.What test is most appropriate for this data and hypothesis?

Exhibit 7-7: A group of curriculum designers has developed a new system for teaching phonics to young children.They randomly selected 24 kindergarten students to receive either the old phonics method or the new phonics method.The designers realized that kindergartens have morning and afternoon classes, so they wanted to build this factor into the research design.The following is the mean, standard deviation, and number for each group. Morning Old New 16.33 13.50 1.03 2.74 6 6 Afternoon 13.17 16.83 3.55 2.14 6 6 The following is an incomplete summary table of the analysis of variance: Time of Day 0.042 Lesson Design 1.042 Interaction Error 128.500 Total 102950 -Refer to Exhibit 7-7.What are the degrees of freedom for Error?

What is the purpose of sampling?

Exhibit 7-10: Choose the appropriate statistic for the following situations. -Refer to Exhibit 7-10.A significantly greater proportion of special education teachers have "burned out" compared to the proportion of regular classroom teachers.

Exhibit 7-11: In a 2 $\times$ 3 experimental design three kinds of treatments (A, B, and C) were used with two groups of subjects (M and N).The number of subjects and the mean of each group are as follows: Treatments =20 =18 =16 =5 =5 =5 subjects =12 =14 =16 =5 =5 =5 The following is the incomplete summary table of multifactor analysis of variance.Complete the table and answer the following questions. Source of variation SS Between columns 0 Between rows 120 Interaction Between groups 200 Within groups Tntal 454 -Refer to Exhibit 7-11.Assume that the F ratios for between rows and interaction are statistically significant, but the F ratio for between columns is not statistically significant.In accepting these results, is it possible that

Exhibit 7-3: A researcher is examining the effects of a computer-based training program designed to teach algebra.The researcher randomly selects subjects for two groups and gives one group the computer training and the other standard teaching methods to see if the results of the two methods differ.The following scores are from the subjects' final test. CBT Control 52 65 55 45 56 47 53 46 50 47 49 33 52 39 53 49 -Refer to Exhibit 7-3.The degrees of freedom for the test are the