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The paper “Facebook Use and Academic Performance Among College Students: A Mixed-Methods Study with a Multi-Ethnic Sample” (Computers in Human Behavior [2015]: 265–272) describes a survey of a sample of 66 male students and a sample of 195 female students at a large university in Southern California. The authors of the paper believed that these samples were representative of male and female college students in Southern California. For the sample of males, the
- a. Do the data provide convincing evidence that the mean time spent on Facebook is not the same for males and for females? Test the relevant hypotheses using α = 0.05.
- b. Do you think it is reasonable to generalize the conclusion from the hypothesis test in Part (a) to the populations of all male college students in the United States and all female college students in the United States? Explain why you think this.
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Introduction To Statistics And Data Analysis
- NutritionResearchers compared protein intake among threegroups of postmenopausal women: (1) women eating astandard American diet (STD), (2) women eating a lactoovo-vegetarian diet (LAC), and (3) women eating a strictvegetarian diet (VEG). The mean ± 1 sd for protein intake(mg) is presented in Table 12.29. 12.5 Using the data in Table 12.29, perform a multiplecomparisons procedure to identify which specific underlyingmeans are different.arrow_forwardThree samples of each of three types of PVC pipe of equal wall thickness are tested to failure under three temperature conditions, yielding the results shown below. Research questions: Is mean burst strength affected by temperature and/or by pipe type? Is there a “best” brand of PVC pipe? Burst Strength of PVC Pipes (psi) Temperature PVC1 PVC2 PVC3 Hot (70º C) 247 299 239 277 287 262 283 275 279 Warm (40º C) 325 341 297 322 319 315 296 335 304 Cool (10º C) 358 375 327 366 352 334 338 359 340 Click here for the Excel Data File (a-1) Choose the correct row-effect hypotheses. a. H0: A1 ≠ A2 ≠ A3 ≠ 0 ⇐⇐ Temperature means differ H1: All the Aj are equal to zero ⇐⇐ Temperature means are the same b. H0: A1 = A2 = A3 = 0 ⇐⇐ Temperature means are the same H1: Not all the Aj are equal to zero ⇐⇐ Temperature means differ a b (a-2) Choose the correct column-effect hypotheses. a. H0: B1 ≠ B2 ≠ B3 ≠ 0 ⇐⇐…arrow_forwardThe following data were obtained from an independent-measures research study comparing three treatment conditions. Use an ANOVA with α=.05 to determine whether there are any significant mean differences among the treatments. Treatment I II III 5 2 7 1 6 3 2 2 2 3 3 4 0 5 5 1 3 2 2 0 4 2 3 5arrow_forward
- A cross-sectional study is conducted to investigate cardiovascular disease (CVD) risk factors among a sample of patients seeking medical care at one of three local hospitals. A total of 500500 patients are enrolled. Based on the following data, we would like to determine if there is a significant association between the family history of CVD and the enrollment site. Enrollment Site Family History of CVD Hospital 1 Hospital 2 Hospital 3 Total Yes 34 8 58 100 No 104 72 224 400 Total 138 80 282 500 Given: The value of the test statistic is χ2= 6.912 Use α=0.1 as the level of significance. The superintendent of Hospital 2 performed the Goodness of Fit Test to test whether 25% of the patients go to Hospital 1, 15% of the patients go to Hospital 2 and 60% of the patients go to Hospital 3. Given: The superintendent found that the pp-value for the test is 0.25091 Let: p1=p1= be the proportion of patients at Hospital 1 p2=p2= be the proportion of patients at…arrow_forwardIn a study, 10 healthy men were exposed to diesel exhaust for 1 hour. A measure of brain activity (called median power frequency, or MPF in Hz) was recorded at two different locations in the brain both before and after the diesel exhaust exposure. The resulting data are given in the accompanying table. For purposes of this exercise, assume that the sample of 10 men is representative of healthy adult males. Subject MPF (in Hz) Location 1before Location 1after Location 2before Location 2after 1 6.4 8.0 6.9 9.4 2 8.6 12.7 9.5 11.2 3 7.4 8.4 6.6 10.2 4 8.6 9.0 9.0 9.7 5 9.8 8.4 9.6 9.2 6 8.9 11.0 9.0 11.9 7 9.1 14.4 7.9 9.3 8 7.4 11.1 8.1 9.1 9 6.7 7.3 7.2 8.0 10 8.9 11.2 7.4 9.3 Construct a 90% confidence interval estimate for the difference in mean MPF at brain location 1 (in Hz) before and after exposure to diesel exhaust. (Hint: See Example 13.7.) (Use ?d = ?before − ?after. Use a table or technology. Round your answers to two decimal places.)…arrow_forwardNutritionResearchers compared protein intake among threegroups of postmenopausal women: (1) women eating astandard American diet (STD), (2) women eating a lactoovo-vegetarian diet (LAC), and (3) women eating a strictvegetarian diet (VEG). The mean ± 1 sd for protein intake(mg) is presented in Table 12.29.*12.1 Perform a statistical procedure to comparethe means of the three groups using the critical-valuemethod.arrow_forward
- In comparing the academic performance of college students who are affiliated with fraternities and those male students who are unaffiliated, a random sample of students was drawn from each of the two populations on a university campus. Summary statistics on the student GWAs are given below. n x s Fraternity 645 2.90 0.47 Unaffiliated 450 2.88 0.42 Test, at the 1% level of significance, whether the data provide sufficient evidence to conclude that there is a difference in average GWA between the population of fraternity students and the population of unaffiliated male students on this university campus. 1. State the hypotheses. 2. Give the critical value and region of rejection. 3. Compute for the standard error of the difference between two means. 4. Compute for the test statistic. Give the probability of the calculated test statistic. 5. Interpret result using both p-value and critical region of rejection. 6. State your conclusion. 7. Construct…arrow_forwardA Michigan study concerning preference for outdoor activities used a questionnaire with a six-point Likert-type response in which 1 designated "not important" and 6 designated "extremely important." A random sample of n1 = 45 adults were asked about fishing as an outdoor activity. The mean response was x1 = 4.9. Another random sample of n2 = 55 adults were asked about camping as an outdoor activity. For this group, the mean response was x2 = 4.0. From previous studies, it is known that σ1 = 1.5 and σ2 = 2.0. Does this indicate a difference (either way) regarding preference for camping versus preference for fishing as an outdoor activity? Use a 5% level of significance. Note: A Likert scale usually has to do with approval of or agreement with a statement in a questionnaire. For example, respondents are asked to indicate whether they "strongly agree," "agree," "disagree," or "strongly disagree" with the statement. (a) What is the level of significance? What is the value of the sample…arrow_forwardA Michigan study concerning preference for outdoor activities used a questionnaire with a six-point Likert-type response in which 1 designated "not important" and 6 designated "extremely important." A random sample of n1 = 42 adults were asked about fishing as an outdoor activity. The mean response was x1 = 4.9. Another random sample of n2 = 55 adults were asked about camping as an outdoor activity. For this group, the mean response was x2 = 4.3. From previous studies, it is known that σ1 = 1.3 and σ2 = 1.2. Note: A Likert scale usually has to do with approval of or agreement with a statement in a questionnaire. For example, respondents are asked to indicate whether they "strongly agree," "agree," "disagree," or "strongly disagree" with the statement. (a) What is the value of the sample test statistic? Compute the corresponding z or t value as appropriate. (Test the difference μ1 − μ2. Round your answer to two decimal places.)(b) Find (or estimate) the P-value. (Round your answer to…arrow_forward
- A Michigan study concerning preference for outdoor activities used a questionnaire with a six-point Likert-type response in which 1 designated "not important" and 6 designated "extremely important." A random sample of n1 = 47 adults were asked about fishing as an outdoor activity. The mean response was x1 = 4.9. Another random sample of n2 = 48 adults were asked about camping as an outdoor activity. For this group, the mean response was x2 = 4.2. From previous studies, it is known that σ1 = 1.4 and σ2 = 1.8. Does this indicate a difference (either way) regarding preference for camping versus preference for fishing as an outdoor activity? Use a 5% level of significance.Note: A Likert scale usually has to do with approval of or agreement with a statement in a questionnaire. For example, respondents are asked to indicate whether they "strongly agree," "agree," "disagree," or "strongly disagree" with the statement. What is the value of the sample test statistic? (Test the difference μ1 −…arrow_forwardAn article in the Journal of Quality Technology (Vol. 13, No. 2, 1981, pp. 111–114) describes an experimentthat investigates the effects of four bleaching chemicals on pulp brightness. These four chemicals wereselected at random from a large population of potential bleaching agents. The data are as follows:a. Test the significance of these chemical types with α=0.05.b. If proven significant, perform a multiple comparison method using Fisher’s LSDarrow_forwardA study was performed on 200 elementary school students to investigate whether regular Vitamin A supplementation was effective in preventing colds during the month of March. 100 were randomized to receive daily Vitamin A supplements during the month of March, and 100 students were randomized to a placebo group (and did not receive Vitamin A) during the same month. The number of students getting at least one cold in March was computed in the two groups, and the results are given in the following 2 X 2 table. Using a 5% level of significance determine whether there is an association between Vitamin A supplementation and prevention of Common Cold ColdNo Cold Vitamin A1585100 Placebo2575100 40160200arrow_forward
- Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill