New Semester Started Get 50% OFF Study Help! --h --m --s Claim Now

Question Answers

Textbooks

Find textbooks, questions and answers

Oops, something went wrong!

Change your search query and then try again

Result Not Found

Books FREE
Study Help
Tutors
AI Study Planner NEW
Sell Books

Search
Sign In
Register

study help
business
nonparametric statistical inference

Fundamentals Of Statistical Reasoning In Education 4th Edition Theodore Coladarci, Casey D. Cobb - Solutions

13. (a) Apply Tukey’s HSD test (α 05) to the results of Problem 12.(b) State your conclusions.14. (a) Construct a 95% confidence interval for each of the mean differences in Problem 12.(b) How do these confidence intervals compare with the answers to Problem 13?(c) Interpret the confidence
12. Professor Loomis selects a sample of second-grade students from each of three schools 12.offering different instructional programs in reading. He wishes to determine whether there are corresponding differences between these schools in the “phonological awareness” of their students.
11. Consider the assumptions underlying the 11. F test for one-way analysis of variance(Section 16.12). Given the following data, do you believe the F test is defensible?(Explain.)X s n Group 1 75 21 36 Group 2 58 16 37 Group 3 60 10 18
10. Which case, Problem 7 or Problem 8, calls for the application of Tukey’s HSD test?(Explain.)
8. Study the following ANOVA summary, and then provide the missing information for the 8.cells designated a–f:Source SS df MS F p Between-groups 1104 (a) (b) 3.00 (c)Within-groups (d) (e) 184 Total 4416 (f)
6. Determine 6. F.05 and F.01 from Table C for each situation below:
5. Consider s2 within and s2 between in Problem 4d.(a) Which is an estimate of inherent variation, and which is an estimate of differential treatment effects?(b) Explain, within the context of this problem, what is meant by “inherent variation” and “differential treatment effects.”
4. A researcher randomly assigns six students with behavioral problems to three treatment 4.conditions (this, of course, would be far too few participants for practical study). At the end of three months, each student is rated on the “normality” of his or her behavior, as determined by
3. You have designed an investigation involving the comparison of four groups. 3.(a) Express H0 in symbolic form.(b) Why can’t H1 be expressed in symbolic form?(c) List several possible ways in which H0 can be false.(d) What’s wrong with expressing the alternative hypothesis as H1: μ1 μ2 μ3
15. Recall the very low correlation between matched pairs in Problem 6 (r12 04). Reanalyze these data as if the scores were from two independent groups of eight participants each.(a) Compare the two sets of results with respect to sX1 X2, the sample t ratio, and the appropriate statistical
13. Parents of 14 entering 13. first graders eagerly volunteer their children for the tryout of a new experimental reading program announced at a PTA meeting. To obtain an “equivalent” group for comparison purposes, each experimental child is matched with a child in the regular program on the
12. You wish to see whether students perform differently on essay tests and on multiplechoice tests. You select a sample of eight students enrolled in an introductory biology course and have each student take an essay test and a multiple-choice test. Both tests cover the same unit of instruction
11. An exercise physiologist compares two cardiovascular fitness programs. Ten matched pairs of out-of-shape adult volunteers are formed on the basis of a variety of factors such as sex, age, weight, blood pressure, exercise, and eating habits. In each pair, one individual is randomly assigned to
10. A psychological testing firm wishes to determine whether college applicants can improve their college aptitude test scores by taking the test twice. To investigate this question, a sample of 40 high school juniors takes the test on two occasions, three weeks apart. The following are the
9. Is one Internet search engine more ef 9. ficient than another? You ask each of seven student volunteers to find information on a specific topic using one search engine (search 1) and then to find information on the same topic using a competing search engine (search 2).Four of the students use
8. Consider Problem 5: 8.(a) Without performing any calculations, what one value do you know for certain would not fall in a 95% confidence interval for μ1 − μ2? (Explain.)(b) Construct and interpret a 95% confidence interval for μ1 − μ2.
7. Consider Problem 6:(a) Without performing any calculations, what one value do you know for certain would fall in a 99% confidence interval for μ1 − μ2? (Explain.)(b) Construct and interpret a 99% confidence interval for μ1 − μ2.(c) What two factors contribute to the width of the
6. The sales manager of a large educational software company compares two training programs 6.offered by competing firms. She forms eight matched pairs of sales trainees on the basis of their verbal aptitude scores obtained at the time of initial employment; she randomly assigns one member of each
5. Professor Civiello wishes to investigate problem-solving skills under two conditions: solv-ing a problem with and without background music. In a carefully controlled experiment involving six research participants, Dr. Civiello records the time it takes each participant to solve a problem when
4. Repeat Problem 3c, except use the direct-difference method.(a) What are the statistical hypotheses?(b) Compute D, SSD, and sD.(c) Test H0.(d) Draw final conclusions.(e) Give the symbols for the quantities from Problem 3 that correspond to μD, D, and sD.(f) Compare your results to those for
3. The following are scores for 3. five participants in an investigation having a pretest–posttest design:Participant ABCDE Pretest 12 6 8 5 9 Posttest 9 8 6 1 6(a) Compute SSpre, SSpost, and rpre,post.(b) From SSpre and SSpost, determine s2 pre and s2 post.(c) Compute sXpre Xpost(d) Test H0:
21. Suppose the following statement were made on the basis of the significant difference reported in Problem 13: “Statistics show that women are higher in emotional intelligence than men.”(a) Is the statement a statistical or nonstatistical inference? (Explain.)(b) Describe some of the limits
20. Is randomization the same as random sampling? (Explain.)
19. Examine Problems 8, 9, 10, 14, and 16. In which would it be easiest to clarify causal 19.relationships? (Explain.)
18. Compare the investigation described in Problem 9 with that in Problem 14. Suppose a significant difference had been found in both—in favor of the children who attended preschool in Problem 9 and in favor of Group 2 in Problem 14.(a) For which investigation would it be easier to clarify the
17. From the data given in Problem 16:(a) Compute and interpret the effect size, d; evaluate its magnitude in terms of Cohen’s criteria and in terms of the normal curve.(b) Calculate and interpret the effect size, ωˆ 2
16. The director of Academic Support Services wants to test the efficacy of a possible intervention for undergraduate students who are placed on academic probation. She randomly assigns 28 such students to two groups. During the first week of the semester, students in Group 1 receive daily
15. (a) Suppose you constructed a 95% confidence interval for μ1 −μ2, given the data in Problem 14. What one value do you already know will reside in that interval?(Explain.)(b) Now construct a 95% confidence interval for μ1 −μ2, given the data in Problem 14.Any surprises?(c) Without
14. A high school social studies teacher decides to conduct action research in her classroom 14.by investigating the effects of immediate testing on memory. She randomly divides her class into two groups. Group 1 studies a short essay for 20 minutes, whereas Group 2 studies the essay for 20 minutes
13. You read the following in a popular magazine: 13. “A group of college women scored significantly higher, on average, than a group of college men on a test of emotional intelligence.” (Limit your answers to statistical matters covered in this chapter.)(a) How is the statistically
12. Parametric statistical tests are tests that are based on one or more assumptions about the nature of the populations from which the samples are selected. What assumptions are required in the t test of H0: μ1 −μ2 0?
11. From the data given in Problem 10:(a) Compute and interpret the effect size, d; evaluate its magnitude in terms of Cohen’s criteria and in terms of the normal curve.(b) Calculate and interpret the effect size, ωˆ 2.
10. You are investigating the possible differences between eighth-grade boys and girls 10.regarding their perceptions of the usefulness and relevance of science for the roles they see themselves assuming as adults. Your research hypothesis is that boys hold more positive perceptions in this regard.
9. An educational psychologist is interested in knowing whether the experience of attending preschool is related to subsequent sociability. She identifies two groups of first graders: those who had attended preschool and those who had not. Then each child is assigned a sociability score on the
8. Does familiarity with an assessment increase test scores? You hypothesize that it does.You identify 11 fifth-grade students to take a writing assessment that they had not experienced before. Six of these students are selected at random and, before taking the assessment, are provided with a
7. For each of the following cases, give the critical value( 7. s) of t:(a) H1: μ1 −μ2 0, n1 6, n2 12, α 05(b) H1: μ1 −μ2 0, n1 12, n2 14, α 01(c) H1: μ1 −μ2 0, n1 14, n2 16, α 05(d) H1: μ1 −μ2 0, n1 19, n2 18, α 01
6. From the data given in Problem 5: 6.(a) Compute and interpret the effect size, d; evaluate its magnitude in terms of Cohen’s criteria and in terms of the normal curve.(b) Calculate and interpret the effect size, ωˆ 2
5. The following results are for two samples, one from Population 1 and the other from 5.Population 2:
4. Assume H0: μ1 − μ2 0 is true. What are the three defining characteristics of the sampling distribution of differences between means?
3. Consider two large populations of observations, A and B. Suppose you have unlimited 3.time and resources.(a) Describe how, through a series of sampling experiments, you could construct a fairly accurate picture of the sampling distribution of XA −XB for samples of size nA 5 and nB 5.(b)
2. A graduate student wishes to compare the high school grade-point averages (GPAs) of males and females. He identifies 50 brother/sister pairs, obtains the GPA for each individual, and proceeds to test H0: μmales −μfemales 0. Are the methods discussed in this chapter appropriate for such a
1. Translate each of the following into words, and then express each in symbols in terms 1.of a difference between means relative to zero:(a) μA μB(b) μA μB(c) μA μB(d) μA μB
25. How do you explain the considerable width of the resulting confidence intervals in Problem 24?
24. From the data in Problems 8a and 8b, determine and interpret the respective 95% 24.confidence intervals for μ.
23. Suppose the director in Problem 22 is criticized for conducting a t test in which there is evidence of nonnormality in the population.(a) How do these sample results suggest population nonnormality?(b) What is your response to this critic?
22. Fifteen years ago, a complete survey of all undergraduate students at a large university 22.indicated that the average student smoked X 8 3 cigarettes per day. The director of the student health center wishes to determine whether the incidence of cigarette smoking at his university has
21. The expression “p 001” occurs in the results section of a journal article. Does this indicate that the investigator used the very conservative level of significance α 001 to test the null hypothesis? (Explain.)
20. Suppose 20. α 0 5 and the researcher reports that the sample mean “approached significance.”(a) What do you think is meant by this expression?(b) Translate the researcher’s statement into symbolic form involving a p value.
19. Translate each of the following statements into symbolic form involving a p value:(a) “The results did not reach significance at the .05 level.”(b) “The sample mean fell significantly below 50 at the .01 level.”(c) “The results were significant at the .001 level.”(d) “The
18. Repeat Problem 17, this time assuming that the investigator has in mind α 01.
17. For each of the following sample 17. t ratios, report the p value relative to a suitable “landmark” (as discussed in Section 13.8). Select among the landmarks .10, .05, and .01, and assume that the investigator in each case has in mind α 05.(a) H1: μ 100, n 8, t 2 01(b) H1: μ 60, n 23, t
16. The following are the times (in seconds) that a sample of 16. five 8-year-olds took to complete a particular item on a spatial reasoning test: X 12 3 and s 9 8. The investigator wishes to use these results in performing a t test of H0: μ 8.(a) From the sample results, what makes you think that
15. Using the data in Problem 8b, an investigator tests H0: μ 11 25 against H1: μ 11 25.(a) Determine t.01.(b) Perform the statistical test.(c) Draw final conclusions.
14. Consider the data in Problem 8a. Suppose the researcher wants to test the hypothesis 14.that the population mean is equal to 72; she is interested in sample departures from this mean in either direction.(a) Set up H0 and H1.(b) Determine t.05.(c) Perform the statistical test.(d) Draw final
13. The task in a particular concept-formation experiment is to discover, through trial and error, the correct sequence in which to press a row of buttons. It is determined from the nature of the task that the average score obtained by random guessing alone would be 20 correct out of a standard
12. For each of the following instances, locate the regions of rejection and the sample results 12.on a rough distribution sketch; perform the test; and give final conclusions about the value of μ.(a) H0: μ 10, H1: μ 10, α 10, sample: 15, 13, 12, 8, 15, 12(b) Same as Problem 12a except α 05
11. From Table B and for df 25, find the proportion of t values that would be:(a) less than t −1 316(b) less than t 1 316(c) between t −2 060 and t 2 060(d) between t −1 708 and t 2 060
10. From Table B, identify the centrally located limits, for 10. df 8, that would include:(a) 90% of t values(b) 95% of t values(c) 99% of t values
9. From Table B, identify the value of t that for df 15:(a) is so high that only 1% of the t values would be higher(b) is so low that only 10% of the t values would be lower
8. Compute the best estimate of 8. σ and σX for each of the following samples:(a) percentage correct on a multiple-choice exam: 72, 86, 75, 66, 90(b) number of points on a performance assessment: 2, 7, 8, 6, 6, 11, 3
7. Comment on the following statement: For small samples selected from a normal population, the sampling distribution of means follows Student’s t distribution.
6. Suppose that 6. df 3. How do the tails of the corresponding t distribution compare with the tails of the normal curve? Support your answer by referring to Tables A and B in Appendix C (assume α 10, two-tailed).
5. Why is the t distribution a whole family rather than a single distribution?
4. You select a random sample of 10 observations and compute s, the estimate of σ. Even though there are 10 observations, s is really based on only nine independent pieces of information. (Explain.)
3. A random sample of 3. five observations is selected. The deviation scores for the first four observations are −5, 3, 1, and −2.(a) What is the fifth deviation score?(b) Compute SS and sX for the sample of all five observations.
2. When would S (Formula 5.2) and s (Formula 13.1) be very similar? very different?(Explain.)
1. Ben knows that the standard deviation of a particular population of scores equals 16. 1.However, he does not know the value of the population mean and wishes to test the hypothesis H0: μ 100. He selects a random sample, computes X, s, and sX, and proceeds with a t test. Comment?
10. For a random sample,X 83 and n 625; assume σ 15.(a) Test H0: μ 80 against H1: 80 α 05 . What does this tell you about μ?(b) Construct the 95% confidence interval for μ. What does this tell you about μ?(c) Which approach gives you more information about μ? (Explain.)
9. (a) If a hypothesized value of μ falls outside a 99% confidence interval, will it also fall outside the 95% confidence interval for the same sample results?(b) If a hypothesized value of μ falls outside a 95% confidence interval, will it also fall outside the 99% confidence interval for the
8. The 99% con 8. fidence interval for μ is computed from a random sample. It runs from 43.7 to 51.2.(a) Suppose for the same set of sample results H0: μ 48 were tested using α 01(two-tailed). What would the outcome be?(b) What would the outcome be for a test of H0: μ 60?(c) Explain your
7. The interval width is much wider in Problem 6a than in Problem 6d. What is the principal reason for this discrepancy? Explain by referring to the calculations that Formula(12.1) entails.
6. Construct a confidence interval for μ that corresponds to each scenario in Problems 15a and 15c–15e in Chapter 11.
5. Consider Problem 4 in Chapter 11, whereX 48, n 36, and σ 10.(a) Construct a 95% confidence interval for μ.(b) Construct a 99% confidence interval for μ.
4. Repeat Problems 2a and 2b with n 9 and then with n 100. What generalization is illustrated by a comparison of the two sets of answers (i.e., n 9 versus n 100)?
3. Explain in precise terms the meaning of the interval you calculated in Problem 2b. 3.Exactly what does “95% confidence” refer to?
2. The results for Rachel 2. ’s sample in Problem 1 isX 33 10 n 36 .(a) Calculate σX .(b) Construct the 95% confidence interval for her population mean score.(c) Construct the 99% confidence interval for her population mean score.(d) What generalization is illustrated by a comparison of your
1. The national norm for third graders on a standardized test of reading achievement is a 1.mean score of 27 σ 4 . Rachel determines the mean score on this test for a random sample of third graders from her school district.(a) Phrase a question about her population mean that could be answered by
20. Suppose a researcher wishes to test H0: μ 100 against H1: μ 100 using the .05 level of significance; however, if she obtains a sample mean far enough below 100 to suggest that H0 is unreasonable, she will switch her alternative hypothesis to H1: 100 (α .05) with the same sample data. Assume
19. Josh wants to be almost certain that he does not commit a Type I error, so he plans to set 19.α at .00001. What advice would you give Josh?
18. What is the relationship between the level of significance and the probability of a Type I error?
17. On the basis of her statistical analysis, a researcher retains the hypothesis, H0 : μ 250.What is the probability that she has committed a Type I error? (Explain.)
16. A researcher plans to test 16. H0: μ 3 50. His alternative hypothesis is H1: 3 50. Complete the following sentences:(a) A Type I error is possible only if the population mean is _____.(b) A Type II error is possible only if the population mean is _____.
15. Given: 15. μ 60, σ 12. For each of the following scenarios, report zα, the sample z ratio, its p value, and the corresponding statistical decision. (Note: For a one-tailed test, assume that the sample result is consistent with the form of H1.)(a) X 53, n 25, α 05 (two-tailed)(b) X 62, n 30,
14. Under what conditions is a directional H1 appropriate? (Provide several examples.)
13. To which hypothesis, H0 or H1, do we restrict the use of the terms retain and reject?
12. Can you make a direct test of, say, H0 75? (Explain.)
11. Explain in general terms the roles of 11. H0 and H1 in hypothesis testing.
10. Repeat Problems 9a 10. –9c, but for H1: 500.(a) Compare these results with those of Problem 9; explain why the two sets of results are different.(b) What does this suggest about which is more likely to give significant results: a twotailed test or a one-tailed test (provided the direction
9. State the critical values for testing 9. H0: μ 500 against H1: μ 500, where(a) α 01(b) α 05(c) α 10
8. Mrs. Grant wishes to compare the performance of sixth-grade students in her district with the national norm of 100 on a widely used aptitude test. The results for a random sample of her sixth graders lead her to retain H0: μ 100 (α 01) for her population.She concludes, “My research proves
7. Consider the generalization from Problem 6. What does this generalization mean for 7.the distinction between a statistically significant result and an important result?
6. Compare the results from Problem 5 with those of Problem 4. What generalization does 6.this comparison illustrate regarding the role of n in significance testing? (Explain.)
5. Repeat Problems 4a 5. –4e, but with n 100.
4. Let 4. ’s say the personnel director in Problem 1 obtained X 48 based on a sample of size 36. Further suppose that σ 10, α 05, and a two-tailed test is conducted.(a) Calculate σX .(b) Calculate z.(c) What is the probability associated with this test statistic?(d) What statistical decision
3. Suppose that the personnel director in Problem 1 wants to know whether the key- 3.boarding speed of secretaries at her company is different from the national mean of 50.(a) State H0.(b) Which form of H1 is appropriate in this instance—directional or nondirectional?(Explain.)(c) State H1.(d)
2. The personnel director in Problem 1 finds her sample results to be highly inconsistent with the hypothesis that μ 50 words per minute. Does this indicate that something is wrong with her sample and that she should draw another? (Explain.)
1. The personnel director of a large corporation determines the keyboarding speeds, on 1.certain standard materials, of a random sample of secretaries from her company. She wishes to test the hypothesis that the mean for her population is equal to 50 words per minute, the national norm for
16. A population of personality test scores is normal with μ 50 and σ 10.(a) Describe the operations you would go through to obtain a fairly accurate picture of the sampling distribution of medians for samples of size 25. (Assume you have unlimited time and resources.)(b) It is known from
15. You randomly select a sample ( 15. n 50) from the population in Problem 14 and obtain a sample mean of X 108. Remember: Although you know that σ 15, you don’t know the value of μ.(a) Would 107 be reasonable as a possible value for μ in light of the sample mean of 108? (Explain in terms of
14. Suppose for a normally distributed population of observations you know that 14. σ 15, but you don’t know the value of μ. You plan to select a random sample (n 50) and use the sample mean to estimate the population mean.(a) Calculate σX .(b) What is the probability that the sample mean will

Showing 3300 - 3400 of 5397

First
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
Last

Step by Step Answers

Services

Sitemap
Fun
Definitions
Become Tutor
Used Textbooks
Study Help Categories
Recent Questions
Expert Questions
Campus Wear
Sell Your Books

Company Info

Security
Copyrights
Privacy Policy
Terms & Conditions
SolutionInn Fee
Scholarship
Online Quiz
Give Feedback, Get Rewards

Get In Touch

About Us
Contact Us
Career
Jobs
FAQ
Student Discount
Campus Ambassador

Secure Payment

Download Our App

© 2026 SolutionInn. All Rights Reserved