Are most student government leaders extroverts? According to Myers-Briggs estimates, about 82% of college student government leaders are extroverts.  Suppose that a Myers-Briggs personality test was given to a random sample of 73 student government leaders attending a national conference and that 56 were found to be extroverts.  Does this indicate that the population proportion of extroverts among college student government leaders is different (either way) from 82%.  Use alpha = 0.01.

4. Data were collected from a pretest and posttest of students taking a two-week course in substance abuse. Would you use a t-test (and if so, which one), or would you use ANOVA? Given the following data, complete the exercise to see if there is a significant difference between the two tests. Pretest Posttest 84 90 85 75 70 89 65 91 71 85 72 79 84 88 85 85 66 82 67 99

A standardized exam's scores are normally distributed. In a recent year, the mean test score was 1471 and the standard deviation was 318. The test scores of four students selected at random are 1910, 1210, 2210, and 1370. Find the z-scores that correspond to each value and determine whether any of the values are unusual. The z-score for 1910 is (Round to two decimal places as needed.)

A research group conducted an extensive survey of 3044 wage and salaried workers on issues ranging from relationships with their bosses to household chores. The data were gathered through hour-long telephone interviews with a nationally representative sample. In response to the question, "What does success mean to you?" 1586 responded, "Personal satisfaction from doing a good job." Let p be the population proportion of all wage and salaried workers who would respond the same way to the stated question. Find a 90% confidence interval for p. (Round your answers to three decimal places.) lower limit       upper limit

Research indicates that stress levels are lowered when petting a dog. . A mood inventory questionnaire is administered to a group of 20-29 - year olds with no do present in the room, and again a month later the same mood questionnaire is administered to the same people with a dog present in the room. Is there a significant difference in the mood scores for when the dog was present or not? Test with a = .05 for two tails.   Person No Dog in Room Dog in Room A 12 14 B 8 7 C 10 13 D 9 9 E 7 13 F 10 12

A research group conducted an extensive survey of 2940 wage and salaried workers on issues ranging from relationships with their bosses to household chores. The data were gathered through hour-long telephone interviews with a nationally representative sample. In response to the question, "What does success mean to you?" 1470 responded, "Personal satisfaction from doing a good job." Let p be the population proportion of all wage and salaried workers who would respond the same way to the stated question. How large a sample is needed if we wish to be 95% confident that the sample percentage of those equating success with personal satisfaction is within 1.6% of the population percentage? (Hint: Use p ≈ 0.50 as a preliminary estimate. Round your answer up to the nearest whole number.) workers

A researcher wants to conduct an experiment to determine which environment is best suited for studying - a library, in one's own room, or outside. A total of 30 university students volunteer to participate in the experiment. The researcher believes that gender has an effect on the results. What are the treatments in the experiment?

The director of student services at Oxnard College is interested in whether women are just as likely to attend orientation as men before they begin their coursework. A random sample of freshmen at Oxnard College were asked what their gender is and whether they attended orientation. The results of the survey are shown below: Data for Gender vs. Orientation Attendance Women Men Yes 440 410 No 238 239 What can be conduded at the a - 0.10 level of significance? For this study, we should use z-test for a population proportion a. The null and alternative hypotheses would be: Ho: Select an answer v Select an answer v Select an answer v (please enter a decimal and note that p1 and ul represent the proportion and mean women and and u2 represent proportion and mean for men.) H: Select an answer v Select an answer v Select an answer v (Please enter a decimal) b. The test statistic ? v (please show your answer to 3 decimal places.) c. The p-value = (Please show your answer to 4 decimal places.) d.…

. A researcher suspects that the actual prevalence of generalized anxiety among children and adolescents is higher than the previously reported prevalence of generalized anxiety disorder among children and adolescents. The previously reported prevalence of generalized anxiety disorder among children and adolescents is 4.1%, and the researcher conducts a study to test the accuracy of the previously reported prevalence of generalized anxiety disorder by recruiting 98 children and adolescents from various pediatricians’ offices and tests them for generalized anxiety disorder using the DSM-5. The researcher determines that the prevalence of generalized anxiety disorder among the participants of the study is 6.8%. The researcher’s hypothesis, for a level of significance of 5%, should resemble which of the following sets of hypothesis? A) H0: p > .041; H1: p = .041; alpha= .05 B) H0: p > .041; H1: p = .041; alpha= .95 C) H0: p = .041; H1: p > .041; alpha= .05 D) H0: p = .041; H1: p…

A sociologist studying New York City ethnic groups wants to determine if there is a difference in income for immigrants from four different countries during their first year in the city. She obtained the data in the following table from a random sample of immigrants from these countries (incomes in thousands of dollars). Use a 0.05 level of significance to test the claim that there is no difference in the earnings of immigrants from the four different countries. Country I Country II Country III Country IV 12.3 8.3 20.4 17.3 9.1 17.2 16.5 8.7 10.9 19.2 22.8 14.2 8.8 10.2 5.5 21.4 16.1   19.2 19.3   (b) Find SSTOT, SSBET, and SSW and check that SSTOT = SSBET + SSW. (Round your answers to three decimal places.) SSTOT =   SSBET =   SSW =   Find d.f.BET, d.f.W, MSBET, and MSW. (Round your answer to three decimal places for MSBET and MSW.) dfBET =   dfW =   MSBET =   MSW =   Find the value of the sample F statistic. (Round your answer to three decimal…