If the subjects receiving a treatment in an experimental study do not know what treatment they are receiving and the experimenter does not know which treatment is being administered to each subject, this is called a:  (i) blind experiment (ii) double-blind experiment (iii) observational study (iv) biased experiment

In the largest clinical trial ever conducted, 401,974 children were randomly assigned to two groups. The treatment group consisted of​ 201,229 children given the Salk vaccine for​ polio, and the other​ 200,745 children were given a placebo. Among those in the treatment​ group, 33 developed​ polio, and among those in the placebo​ group, 115 developed polio. If we want to use the methods for testing a claim about two population proportions to test the claim that the rate of polio is less for children given the Salk​ vaccine, are the requirements for a hypothesis test​ satisfied? Explain.   A The requirements are not​ satisfied; the samples are not simple random samples that are independent.   B. The requirements are​ satisfied; the samples are simple random samples that are​ independent, and for each of the two​ groups, the number of successes is at least 5 and the number of failures is at least 5.   C. The requirements are​ satisifed; the samples are simple random samples…

Question #10  Please explain The three principles of designing experiments are to control, randomize, and replicate. Which of the following statements is not true about these important principles? Considering (controlling) more variables in planning an experiment helps ensure each study group is similar to the other study groups. Using a control group with a placebo is important since otherwise folks in the control group may behave differently than those in the treatment group. Randomizing individuals into groups is one component to prevent accidental bias from creeping into a study. We can always generalize the result of a study to the greater population so long as we randomize which patients go into which study groups. Studying many cases (e.g. including many patients in a study) is often more helpful than just including a few cases in the study. If we collect more information on each case (e.g. take repeated measurements on each individual) that might be helpful to obtaining more…

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In the book Business Research Methods, Donald R. Cooper and . William Emory (1995) discuss a manager who wishes to compare the effectiveness of two methods for training new salespeople. The authors describe the situation as follows: The company selects 22 sales trainees who are randomly divided into two equal experimental groups-one receives type A and the other type B training. The salespeople are then assigned and managed without regard to the training they have received. At the year's end, the manager reviews the performances of salespeople in these groups and finds the following results: Average Weekly Sales. Standard Deviation HO: μA - μB ≤ t= (a) Set up the null and alternative hypotheses needed to attempt to establish that type A training results in higher mean weekly sales than does type B training. Reject Do not reject Do not reject Do not reject Very strong A Group 3.214 X₁ $1,352 $1= 224 Confidence interval [ B Group X2 = $1,000 $2 = 286 (b) Because different sales trainees…

A high school track coach wanted to test whether giving the students an energy drink could affect performance during the 100 meter race. The coach split the 26 boys into two equal sized groups, where Group 1 was given the energy drink and Group 2 was not. The 100 meter race times were recorded during practice and shown in the table below. What inference can be made about the results? Group 1 Group 2 12.2 13 12.5 12.3 13.3 12.8 12.9 13 13 13.8 12.1 13 13 13 13 13 12.1 13 13 13 12.1 13 12.8 13 13 12.6     Mean: 12.7 Mean: 13   Since the simulation shows ( many cases or free cases )?  where a mean  difference of ( solve for this answer )   or less occurred when the groups were re-randomized, it can be inferred that the mean difference observed in the study was ( very possibly or very unlikely )  ?due to the random assignment of participants into groups, so the results of the study are (…

Hamilton County Judges Reporter Kristen DelGuzzi of The Cincinnati Enquirer is writing a piece about the effectiveness of judges in Hamilton County, Ohio. In an overwhelming majority of the cases disposed, the verdict stands as rendered. However, some cases are appealed, and of those appealed, some of the cases are reversed. Over a three-year period the Hamilton County Common Pleas Court, Domestic Relations Court, and Municipal Court handled 182,908 cases. The purpose of the newspaper's study is to evaluate the performance of each court and the judges who render their decisions. Appeals are often the result of mistakes made by judges, and the newspaper wanted to know which court and which judges were doing a good job and which were making too many mistakes. You have been hired to assist in the data analysis at the court level (judge-level analysis will be done at a later time). You must use your knowledge of probability and conditional probability to help determine the likelihood of…

A community college wants to find out how students enrolled in remote courses feel about remote learning,so a random sample of students is needed to form a focus group. You are a data scientist in charge ofidentifying a sample of students for the focus group.  Why is it important to select a random sample in this case? Would it be ok for the college to ask for volunteers for the focus group? Why or why not? Are there pros and cons for each samplingapproach? Which is best and why? Could Stratified Random Sampling have also been used? What benefits might this approach have inselecting the sample of students for the focus group? Explain or give an example of how this could bedone.  874786667172747718114301699108421009846176806728505883964138722994692957574451054463441011799713150445482678936083128648618194219333913373855511070208365643664235172417102465259067655654964950492581611669287944720629621174445585225321068039268392266267994

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is described below. NOTE: If the method is experimental, indicate if it is a true experiment or quasi experiment. 1. I get 30 people and use random assignment to divide the people into two groups. One group reads an article about the statistics of injuries and deaths caused by people using smart phones while driving, the other group watches a short video about a person who killed someone while using their smart phone. Both groups are then monitored to see if either of these made a difference in how often these people use their smart phones use while behind the wheel. What method would that study be? 2. What method asks a series of questions that are all planned in advance?