A study is planned to compare two weight-loss programs in patients who are obese. The first program is based on restricted caloric intake and the second is based on specific food combinations. The study will involve 20 participants and each participant will follow each program. The programs will be assigned in random order (i.e., some participants will first follow the restricted-calorie diet and then follow the food-combination diet, whereas others will first follow the food-combination diet and then follow the restricted-calorie diet). The number of pounds lost will be compared between diets. Identify the type of study proposed and indicate its specific strengths and weaknesses.

A study is planned to compare two weight-loss programs in patients who are obese. The first program is based on restricted caloric intake and the second is based on specific food combinations. The study will involve 20 participants and each participant will follow each program. The programs will be assigned in random order (i.e., some participants will first follow the restricted-calorie diet and then follow the food-combination diet, whereas others will first follow the food-combination diet and then follow the restricted-calorie diet). The number of pounds lost will be compared between diets. Identify the type of study proposed and indicate its specific strengths and weaknesses.

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...

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Part 1 of 4 A pharmaceutical company claims their new diabetes medication results in less variance in a patient's glucose level than if the patient were on no medication at all. An endocrinologist wishes to test this claim. She divides participants randomly into two groups. Group A consists of 20 diabetics who received the medication; group B consists of 26 diabetics who received a placebo. After two weeks, the blood sugar level of each patient in each group was measured with the following results (in mg/dL): Group A: 77.8, 229.4, 199.9, 110.1, 180.2, 116.1, 139.7, 171.1, 37.4, 158.1, 88.4, 195.5, 246.1, 142.4, 178.1, 105.5, 179.6, 146.1, 78.8, 123.7 Group B: 124.5, 130.1, 136, 162.8, 113.4, 72.8, 142.6, 50.3, 179.8, 197, 230, 194.3, 171, 109.3, 114.4, 107.5, 114.7, 195.3, 127.7, 126.4, 85.6, 166.7, 182.3, 113.5, 216.7, 162.8 Perform a hypothesis test using a 6% level of significance to test the pharmaceutical company's claim. Step 1: State the null and alternative hypotheses. Ho: Ha:…
A report describes a survey of 500 licensed drivers. Each driver in the sample was asked if they would prefer to keep complete control of the car while driving, to use a partially self-driving car that allowed partial driver control, or to turn full control over to a driverless car. Suppose that it is reasonable to regard this sample as a random sample of licensed drivers in the United States, and that you want to use the data from this survey to decide if there is evidence that fewer than half of all licensed drivers in the United States prefer to keep complete control of the car while driving. (d) The actual sample proportion observed in the study was p̂ = 0.44. Based on this sample proportion, is there convincing evidence that fewer than 50% of licensed drivers prefer to keep complete control of the car when driving, or is the sample proportion consistent with what you would expect to see when the null hypothesis is true? Support your answer with a probability calculation. (Round…
In a 2009 study, a team of researchers recruited 38 men and divided them randomly into two groups - treatment or control. The also recruited 38 women and they randomly placed half the participants into the treatment group and the other half into the control group. One group was given 25 grams of chia seeds twice a day, and the other was given a placebo. The subjects volunteered to be a part of the study. After 12 weeks, the scientists found no significant difference between the groups in appetite or weight loss. Which of the following is true. (i) This is an observational study (ii) Blinding is used in this study because subjects in the control group recieved a placebo, so that htey were blinded to the treatment they recieved. (iii) We can safely generalize the conclusion (that chia seeds have no significant effect on appetite or weight loss) from the participants to the population at large because randomization is used when assigning participatns to groups.
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The authors of a research article were interested in the effect on female viewers of watching movies in which female heroines were portrayed in roles that focus on their sex appeal. They carried out an experiment in which female college students were assigned at random to one of two experimental groups. The 24 women in one group watched 13 minutes of scenes from a certain superhero film series and then responded to a questionnaire designed to measure body esteem. Lower scores on this measure correspond to lower body satisfaction. The 29 women in the other group (the control group) did not watch any video prior to responding to the questionnaire measuring body esteem. For the women who watched the video, the mean body esteem score was 4.44 and the standard deviation was 1.02. For the women in the control group, the mean body esteem score was 5.07 and the standard deviation was 0.96. For purposes of this exercise, you may assume that the distribution of body esteem scores for each of the…
A researcher is conducting an experimental study on the effect of aspirin on heart attack risk. In order to assign who will receive aspirin and who will receive a placebo, she first divides her study into three age groups (18-29, 30-49, and 50 or older). She then randomly assigns individuals within these age groups to either receive aspirin or the placebo. This is an example of a cluster ?
A group of 600 patients who suffer from seasonal allergies is asked to participate in a study to determine the effectiveness of a new medication. The patients are divided randomly into two groups, one was given the actual medication and one received a placebo pill. After 2 months of treatment, 64% of the patients who took the medication had fewer allergy symptoms, while only 36% of those who took the placebo had fewer allergy symptoms. a. What is the treatment variable? b. What is the response (or outcome) variable? c. Was this an observational study or a controlled experiment? Explain how you know. d. Assuming the rest of the study was well-designed, use your answers to discuss whether it would be reasonable to conclude that taking the new medication caused fewer allergy symptoms.
You are interested in testing if there is a difference in weight-loss between 3 popular diet types; low calorie, low fat and low carb. Participants are randomly assigned one of the three groups or a control group. The control group will be told that are participating in a weight-loss study, but will not be following any particular diet. This is to study the placebo effect, weight-loss from just participating in the study. At the start of the study, each participant's weight is recorded in pounds. After 8 weeks they are weighed again, and the weight difference is recorded. A positive value represents a weight loss while a negative value represents a weight gain. Test at 10% significance. Round answers to 3 decimal places. Diet Type Low Calorie Low Calorie Low Calorie Low Calorie Low Calorie Low Fat Low Fat Low Fat Low Fat Low Fat Low Carb Low Carb Low Carb Low Carb Low Carb Control Control Control Control Control Pounds Lost 5.3 6.6 10.5 6.4 8.9 5 4 0.2 2.9 2.6 4.6 2.9 0.8 2.4 2.5 1.9…
A market research group is interested in estimating the market share of three airline companies, A, B and C, operating on a particular flight path. These three airlines are the only companies operating on this route. Airline B claim that they have 50% of the business with the remaining percentage shared equally amongst airlines A and C, i.e. 25% each. The market research group decide to carry out an independent study and question a random sample of 97 people visiting an airport on a particular day. Each person was given price, timetables and service details of flights on this route for each of the three airlines. Provided with this information they were asked to select their airline of choice.The survey revealed the following observed frequencies Airline A - 26 Aurline B - 49 Airline C - 22 Test if there is any evidence to suggest that the airline's claim is incorrect, at significance level α = 0.05. Complete the test by answering the following questions : Which of the following is the…
Recent research findings have shown that older people who practice ballroom dancing are 77% less likely to experience dementia compared to those senior citizens who did not dance. Drawing on this surprising result, Dr. Anders Ericsson thinks that ballroom dancing may also reduce one's level of stress to a greater extent than conventional exercise routines. To validate his claim Dr. Ericsson has randomly selected 100 senior citizens who were then randomly split into two groups, with the first group practicing ballroom dancing 3 times a week and the second group undergoing a conventional exercise regiment 3 times a week also. The measures of stress were assessed for each participant after the study was completed. What is the most appropriate set of hypotheses for this study? HO: μD- 0; H1: μD 0 HO: µD = 0; H1: µD > 0 %3D HO: udance - pexercise = 0; H1: µdance - pexercise <0