Dr. S. Oberman has the research hypothesis that drivers who have consumed one drink are actually slightly better (score higher on a driving test) than drivers who have had no alcohol. (One drink, she believes, makes them relaxed and not as nervous.) She tests this by having subjects take a standard driving test. We know that completely sober, college-student drivers score an average of 75 on this test, where high scores mean better driving. Lon Sum, Dr. S. Oberman's research assistant, draws a random sample of 64 from a population of college students, and gives them one drink. In this sample, the mean score on the test is 78, and the standard deviation is 24. After discussing it with her colleague, Professor Vi Russ, Dr. Oberman sets her alpha level at .05. Given the results of her study, what decision should she make? Reject the null hypothesis, since the mean is above 75 O Reject the null hypothesis, since the Z-score is greater than 0 O Reject the null hypothesis, since the Z-score is greater than the critical value when alpha is at .05 Do not reject the null hypothesis; the results are likely due to chance factors.

Dr. S. Oberman has the research hypothesis that drivers who have consumed one drink are actually slightly better (score higher on a driving test) than drivers who have had no alcohol. (One drink, she believes, makes them relaxed and not as nervous.) She tests this by having subjects take a standard driving test. We know that completely sober, college-student drivers score an average of 75 on this test, where high scores mean better driving. Lon Sum, Dr. S. Oberman's research assistant, draws a random sample of 64 from a population of college students, and gives them one drink. In this sample, the mean score on the test is 78, and the standard deviation is 24. After discussing it with her colleague, Professor Vi Russ, Dr. Oberman sets her alpha level at .05. Given the results of her study, what decision should she make? Reject the null hypothesis, since the mean is above 75 O Reject the null hypothesis, since the Z-score is greater than 0 O Reject the null hypothesis, since the Z-score is greater than the critical value when alpha is at .05 Do not reject the null hypothesis; the results are likely due to chance factors.

A First Course in Probability (10th Edition)

10th Edition

ISBN:9780134753119

Author:Sheldon Ross

Publisher:Sheldon Ross

Chapter1: Combinatorial Analysis

Section: Chapter Questions

Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...

See similar textbooks

Similar questions

Cocaine addiction is hard to break. Addicts need cocaine to feel any pleasure, so perhaps giving them an antidepressant drug will help. An experiment assigned chronic cocaine users to take either an antidepressant drug called desipramine, lithium, or a placebo. Lithium is a standard drug to treat cocaine addiction. A placebo is a dummy drug, used so that the effect of being in the study but not taking any drug can be seen. Here are the results after three years. Desipramine Lithium Placebo Relapse 11 20 23 No relapse 15 What proportion of subjects did not relapse? (round your answer to three decimal places)
Respond to the question with a concise and accurate answer, along with a clear explanation and step-by-step solution, or risk receiving a downvote.
Some people seem to believe that you can fix anything with duct tape. Even so, many were skeptical when researchers announced that duct tape may be a more effective and less painful alternative than liquid nitrogen, which doctors routinely use to freeze warts. An article described a study conducted at a medical center. Patients with warts were randomly assigned to either the duct tape treatment or the more traditional freezing treatment.Those in the duct tape group wore duct tape over the wart for 6 days, then removed the tape, soaked the area in water, and used an emery board to scrape the area. This process was repeated for a maximum of 2 months or until the wart was gone. Data consistent with values in the article are summarized in the following table. Treatment n Number with WartSuccessfully Removed Liquid nitrogen freezing 100 60 Duct Tape 103 88 Do these data suggest that freezing is less successful than duct tape in removing warts? Test the relevant hypotheses using…
Auditors must make judgments about various aspects of an audit on the basis of their own direct experience, indirect experience, or a combination of the two. In a study, auditors were asked to make judgments about the frequency of errors to be found in an audit. The judgments by the auditors were then compared to the actual results. Suppose the following data were obtained from a similar study; lower scores indicate better judgments. If answer is zero enter "0". Direct Indirect Combination 17.8 16.9 24.7 18.6 21.2 23.6 16.4 20.8 21.8 18.0 19.1 27.2 20.2 23.3 27.7 15.3 20.5 24.9 13.2 21.9 24.8 Source Sum of Squares Degrees Mean Square F p-value of Variation (to 2 decimals) of Freedom (to 2 decimals) (to 2 decimals) (to 2 decimals) Treatments Error Total Use a = 0.05 to test to see whether the basis for the judgment affects the quality of the judgment. The p-value is - Select your answer - What is your conclusion? - Select your answer -
Read through this scenario and look at the data that was collected. State the null and all possible research hypotheses. Review the results below (I used SPSS) and answer the questions that follow. Scenario: A researcher wants to see if gender and / or income affects the total amount of help given to a stranger who is sitting on the side of a busy road with a sign asking for help. The independent variables are gender, income, and the interaction of gender and income. The dependent variable is total help. He wants to know if one or both factors – or the interaction of the two - affects the total amount of help offered. Because he is analyzing two independent variables (gender and income), he used a factorial ANOVA. His results show the main effect of each of the independent variables on the dependent variable (total help) and the interaction effect. The researcher is using a 95% confidence interval which means that he wants to be at least 95% sure that his independent variables…
An anger-management course claims that, after completing its seminar, participants will lose their tempers less often. Always a skeptic, you decide to test this claim. A random sample of 12 seminar participants is chosen, and these participants are asked to record the number of times that they lost their tempers in the two weeks prior to the course. After the course is over, the same participants are asked to record the number of times that they lost their tempers in the next two weeks. The following table lists the results of the survey. Using these data, test the claim at the 0.10 level of significance assuming that the population distribution of the paired differences is approximately normal. Let participants before completing the anger-management course be Population 1 and let participants after completing the anger- management course be Population 2. Number of Times Temper Was Lost during a Two-Week Period 10 11 6 3 4 59 12 12 11 4 8 12 6 4 5 4 4 11 13 12 5 Before After Copy Data…
A team physician has determined that of all the athletes who were treated for minor back pain, 72% responded to an analgesic, 59% responded to a muscle relaxant, and 44% responded to both forms of treatment. What percent of the athletes who were treated responded to the muscle relaxant but not to the analgesic? What percent of the athletes who were treated did not respond to either form of treatment?
Say Dr. Callahan measures her students' levels of narcissism. Her findings reveal that narcissism rates are higher in her male students versus her female students, a finding that is consistent with previous research. She also finds that the overall class average (11.5 out of 20) is lower than typical undergraduates' levels (15.5). Which of the following statements about this scenario is TRUE? She can conclude that being a SSU student is associated with lower levels of narcissism. She needs to be skeptical of her findings because she did not have a random sample. She needs to be skeptical of her findings because she did not have random assignment. She can conclude that her sample is externally valid because it replicates previous research. She can conclude that being a SSU student causes narcissism to decrease.
In the Preview for this Chapter, we discussed a study by McGee and Shevlin (2009) demonstrating that an individual’s sense of humor had a significant effect on how the individual was perceived by others. In one part of the study, female college students were given brief descriptions of a potential romantic partner. The fictitious male was described positively and, for one group of participants, the description also said that he had a great sense of humor. Another group of female students read the same description except it now said that he has no sense of humor. After reading the description, each participant was asked to rate the attractiveness of the man on a seven-point scale from 1 (very unattractive) to 7 (very attractive) with a score of 4 indicating a neutral rating. a. The females who read the “great sense of humor” description gave the potential partner an average attractiveness score of M = 4.53 with a standard deviation of s = 1.04. If the sample consisted of n = 16…
this is part 2 of a question. Although older Americans are most afraid of crime, it is young people who are more likely to be the actual victims of crime. It seems that older people are more cautious about the people with whom they associate. A national survey showed that 10% of all people ages 16-19 have been victims of crime.† At a high school, a random sample of n = 66 students (ages 16-19) showed that r = 11 had been victims of a crime. Note: For degrees of freedom d.f. not in the Student's t table, use the closest d.f. that is smaller. In some situations, this choice of d.f. may increase the P-value a small amount and thereby produce a slightly more "conservative" answer. Find a 90% confidence interval for the proportion of students in this school (ages 16-19) who have been victims of a crime. (Round your answer to three decimal places.) lower limit upper limit (c) How large a sample size should be used to be 95% sure that the sample proportion p̂ is within…
Dorinda is in second grade. She asks 6 of her classmates if they like to wear friendship bracelets. Four of her classmates said yes. Based on her findings, would it be reasonable to assume that about 2/3 of the pupils at her school (which has kindergarten through fifth grade) would also like to wear friendship bracelets? Why or why not?
Swearing is a common, almost reflexive, response to pain. Whether you knock your shin into the edge of a coffee table or smash your thumb with a hammer, most of us respond with a streak of obscenities. One question, however, is whether swearing has any effect on the amount of pain that you feel. To address this issue, Stephens, Atkins, and Kingston (2009) conducted an experiment comparing swearing with other responses to pain. In the study, participants were asked to place one hand in icy cold water for as long as they could bear the pain. Half of the participants were told to repeat their favorite swear word over and over for as long as their hands were in the water. The other half repeated a neutral word. The researchers recorded how long each participant was able to tolerate the ice water. After a brief rest, the two groups switched words and repeated the ice water plunge. Thus, all the participants experienced both conditions (swearing and neutral) with half swearing on their first…