- The following are body mass index (BMI) scores measured in 12 patients who are free of diabetes and participating in a study of risk factors for obesity. Body mass index is measured as the ratio of weight in kilograms to height in meters squared. Generate a 95% confidence interval estimate of the true BMI. 25 27 31 33 26 28 38 41 24 32 35 40

- Consider the data in Problem #1. How many subjects would be needed to ensure that a 95% confidence interval estimate of BMI had a margin of error not exceeding 2 units?

3. A clinical trial is run to investigate the effectiveness of an experimental drug in reducing preterm delivery to a drug considered standard care and to placebo. Pregnant women are enrolled and randomly assigned to receive either the experimental drug, the standard drug or placebo. Women are followed through delivery and classified as delivering preterm (< 37 weeks) or not. The data are shown below.

Preterm Delivery |
Experimental Drug |
Standard Drug |
Placebo |

Yes |
17 |
23 |
35 |

No |
83 |
77 |
65 |

Is there a statistically significant difference in the proportions of women delivering preterm among the three treatment groups? Run the test at a 5% level of significance.

**Chi-Square Test: Experimental Drug, Standard Drug, Placebo **

4. Consider the data presented in problem #4. Previous studies have shown that approximately 32% of women deliver prematurely without treatment. Is the proportion of women delivering prematurely significantly higher in the placebo group? Run the test at a 5% level of significance.

5. A study is run comparing HDL cholesterol levels between men who exercise regularly and those who do not. The data are shown below.

Regular Exercise |
N |
Mean |
Std Dev |

Yes |
35 |
48.5 |
12.5 |

No |
120 |
56.9 |
11.9 |

6. A clinical trial is run to assess the effects of different forms of regular exercise on HDL levels in persons between the ages of 18 and 29. Participants in the study are randomly assigned to one of three exercise groups – Weight training, Aerobic exercise or Stretching/Yoga – and instructed to follow the program for 8 weeks. Their HDL levels are measured after 8 weeks and are summarized below.

Exercise Group |
N |
Mean |
Std Dev |

Weight Training |
20 |
49.7 |
10.2 |

Aerobic Exercise |
20 |
43.1 |
11.1 |

Stretching/Yoga |
20 |
57.0 |
12.5 |

Is there a significant difference in mean HDL levels among the exercise groups? Run the test at a

5% level of significance. HINT: SSwithin = 21,860.

7. Consider again the data in problem #6. Suppose that in the aerobic exercise group we also measured the number of hours of aerobic exercise per week and the mean is 5.2 hours with a standard deviation of 2.1 hours. The sample correlation is -0.42.

a) Is there evidence of a significant correlation between number of hours of exercise per week and HDL cholesterol level? Run the test at a 5% level of significance.

b) Estimate the equation of the regression line that best describes the relationship between number of hours of exercise per week and HDL cholesterol level (Assume that the dependent variable is HDL level).

c) Estimate the HDL level for a person who exercises 7 hours per week.

d) Estimate the HDL level for a person who does not exercise.

8. The following data were collected in a clinical trial to compare a new drug to a placebo for its effectiveness in lowering total serum cholesterol. Generate a 95% confidence interval for the difference in mean total cholesterol levels between treatments.

New Drug (n=75) |
Placebo (n=75) |
Total Sample (n=150) |
|||

Mean (SD) Total Serum Cholesterol |
185.0 (24.5) |
204.3 (21.8) |
194.7 (23.2) |
||

% Patients with Total Cholesterol < 200 |
78.0% |
65.0% |
71.5% |
||

9. A small pilot study is conducted to investigate the effect of a nutritional supplement on total body weight. Six participants agree to take the nutritional supplement. To assess its effect on body weight, weights are measured before starting the supplementation and then after 6 weeks. The data are shown below. Is there a significant increase in body weight following supplementation? Run the test at a 5% level of significance.

Subject |
Initial Weight |
Weight after 6 Weeks |

1 |
155 |
157 |

2 |
142 |
145 |

3 |
176 |
180 |

4 |
180 |
175 |

5 |
210 |
209 |

6 |
125 |
126 |

10. Answer True or False to each of the following

a) The margin of error is always greater than or equal to the standard error.

b) If a test is run and p=0.0356, then we can reject H_{0 }at α=0.01.

c) If a 95% CI for the difference in two independent means is (-4.5 to 2.1), then the point estimate is -2.1.

d) If a 95% CI for the difference in two independent means is (2.1 to 4.5), there is no significant difference in means.

Why Work with Us

Top Quality and Well-Researched Papers

We always make sure that writers follow all your instructions precisely. You can choose your academic level: high school, college/university or professional, and we will assign a writer who has a respective degree.

Professional and Experienced Academic Writers

We have a team of professional writers with experience in academic and business writing. Many are native speakers and able to perform any task for which you need help.

Free Unlimited Revisions

If you think we missed something, send your order for a free revision. You have 10 days to submit the order for review after you have received the final document. You can do this yourself after logging into your personal account or by contacting our support.

Prompt Delivery and 100% Money-Back-Guarantee

All papers are always delivered on time. In case we need more time to master your paper, we may contact you regarding the deadline extension. In case you cannot provide us with more time, a 100% refund is guaranteed.

Original & Confidential

We use several writing tools checks to ensure that all documents you receive are free from plagiarism. Our editors carefully review all quotations in the text. We also promise maximum confidentiality in all of our services.

24/7 Customer Support

Our support agents are available 24 hours a day 7 days a week and committed to providing you with the best customer experience. Get in touch whenever you need any assistance.

Try it now!

How it works?

Follow these simple steps to get your paper done

Place your order

Fill in the order form and provide all details of your assignment.

Proceed with the payment

Choose the payment system that suits you most.

Receive the final file

Once your paper is ready, we will email it to you.

Our Services

No need to work on your paper at night. Sleep tight, we will cover your back. We offer all kinds of writing services.

Essays

No matter what kind of academic paper you need and how urgent you need it, you are welcome to choose your academic level and the type of your paper at an affordable price. We take care of all your paper needs and give a 24/7 customer care support system.

Admissions

Admission Essays & Business Writing Help

An admission essay is an essay or other written statement by a candidate, often a potential student enrolling in a college, university, or graduate school. You can be rest assurred that through our service we will write the best admission essay for you.

Reviews

Editing Support

Our academic writers and editors make the necessary changes to your paper so that it is polished. We also format your document by correctly quoting the sources and creating reference lists in the formats APA, Harvard, MLA, Chicago / Turabian.

Reviews

Revision Support

If you think your paper could be improved, you can request a review. In this case, your paper will be checked by the writer or assigned to an editor. You can use this option as many times as you see fit. This is free because we want you to be completely satisfied with the service offered.